METAPHYSICS BOOK GAMIMA: ARISTOTLE AND THE LOGIC OF SUBSTANCE

Rosemary Anitra Laycock

Subrnitted in partial fulfillment of the requirements for the degree of Master of Arts

Dalhousie University Halifax, Nova Scotia August 1998

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Page vi

1

Bekker No. lOO3a2l- lOO3a33 This Science is an Ontology . 6 1003a2 1- 1003a33 Being has a nature - 6 loO3a33- lûû5a 18 Fmm Oatology to Ousiology: Being and Unity II& "Ev . 9 IOMa33-1003b23 Being is not self-identicai in a plurality . 12 1003622-1004a2 Being and unity are correlative - 16 1004a3-1004a9 Al1 substances fdI under one science 18 1004a9-1004a20 The nature of non-king . 11 1004a20-1-18 One science considers kingand its attributes 23

1005a19-1005b34 From OrisioIogy to Aitiology 2'7

1005b35- 1009a5 Formal Cause: The Logic of Same and Other 33 1006a18100&3 The PNC as an ontological principle . 34 1006a29- 1006b34 Being as the subject of defiuition . 34 1006h35- 1 ma8 Being as the self-identical . 36 1007a9-1007bU3 Being as substance and essence - 37 l007bl8- 1008a2 Being as potentiai . 41 1~-1009aS The PNC as an epistemological principle . 42 1-7- 1OOgb3 Without assertion & denial there is no finitude for thought . 44 I008b2- 1009rt5 Al1 men make unqualified j udgements 46 lOO9a5-lOl la3 The Unchanging Foiindation of the Senst'Me 50 100%51009a22 Those rejectiop substance & essence have a common position 50 1009a33-1999b12 The apparently contradictory nature of the sensible . 53 1009b12- 1Ob38 The identification of knowledge with sensation . 57 101Chl-1010a37 The exposition of the fundamental nature of change 60 1010bl- lOlOb3 Imagination is not sensation 67 lOlOb4- lOIObl4 Objects of knowing exist apart from the perceiving subject . 70 1010b14-101 la3 Sensible objects exist apart from the perceiving subject . 75 1010b14- 1010b30 Sensation of the proper object of sense is not false . 76 1010h3(1101 la3 The sensible world has a reality apart from sensation . 77

1011s3-101lb22 r6 Everything Cannot be Relative 80 101 Ia3-101 la14 There can be no ultirnate criterion of judgement - 80 101 lal6-101 lbl The assertion that al1 appearances are true must be qua1 ified 83 1011b4-IO1 lb7 The perceiving subjectis not the cause of the the sensible - 84 101 1b7-1011b12 The kfutationof Rotagoras reveals the nature of the relative 8s 101 1bl5lOl lb23 Contrarietv is a determinate privation . 88 CONTENTS

Bekker No. page

101 1 b23- 10 12a28 I7 Potentiaiity is Not Indeterminate , . 89 101 1b29- 101331 Contrariety is distinguishablefrom contradiction in general . 90 101212-103a17 There can be no intermediate between contradictones . 91 1012a17-101%28 The beginning must be with definition -93

1012a29-1012b31 f8 TowardsaTbedogy:TheUnityofTiiinkmg&Being . 94 101'%i2% 1012b33 Definition is the bais of knowing . .% 1012bz-1013b3 1 The establishment of the bisfor the stability of king . 95 ABSTRACT

Book r is Aristotle's response to the most pressing philosophical issue of bis day, Parmenides' demand that it is necessary to be able to think and to speak being. The challenge of Parmenides and the pround for Aristotie's own fint philosophy is found to be vested ultimately in soiving the problem that is presented by change and showing how non- being, as that which is in motion. can be said to be. It is the primary opposition of the unchanging Parmenidean One and the ever-changing Heraclitean flux that is the unspoken and overarchiog Dnopiu of Book T: and in the emergent recognition in r4-8 of Aristotle's own fundamental metaphy sical princi ples of essence and of po tency and act there is found the basis for a new understanding of the nature of reality. As pnnciple, substance is 'what is and is one', the central conception of beinp and unity npoç Év. As formal cause it defines an essential nature and delineates it from dl that it is not through an operational logic which extends to the whole of reality, encompassing both the actual and the potential. In establishing in Book r those key relationships which draw king xpbç Èv and SUvapiq npiy n into a conception of substance ordered é@&i~to the unrnoved mover as its ÙpXil, Anstotle draws free of the scepticism of those for whom truth resides only in the subjectivity of appearances and reveais the direction that thought will follow in the Metaphysics in reachinp its goal, this science as Ckokyticfi. The text and bglish translation of the Metaphysics used in this study are those of Sir David Ross, except that wbere necessary to clarify a philosophic point a more literal translation is given. For their helpful feedback on the interpretation of the text and invaluable insights into the thought of Anstotie. 1 thank in particular my thesis supervisor, Dr. D. K. House, and my readers, Dr. J. P. Atherton and Dr. A. M. Johnston. As Aristotle himself well recognized although it is in contemplation that there lies the geatest happiness, a human king needs also a modicum of extemal goods. In this respect, the support provided for this activity by the Tnistees of the Killam Foundation is gratefully acknowledged.

vii INTRODUCTION

Aristotle's deceptively simple and matter of fact opening statement to the Mefaphvsics embodies within a few short words the whole driving force of the argument. It is of the nature of man to wonder, to desire to know, and observations bear witness to this since, "as is coafirmed by the facts"(981b22). 'this science' is pursued for its own sake and not for any advantage. The momentum that pmpels the search fonuard is that desire, nascent within mankind, to escape fmm self-cooscious ignorance. This desire if it is to have any meaning must be ordered to an identxable end. At firsî men see the end in solving the obvious diff~cultiesbut graduaily they are moved, forced forward by the tmth itself, to seek higher and higber causes as knowledge is ordered ultimately to the first principle. for that which the human desires most God possesses. "ALI the sciences, indeed, are more necessary than this but none is bettern (983a10). It is that wonder, which begins in the awareness of an end not yet possessed, that leads inexorabty to the search for the imer connectedness which is the of reality itself.

Whatever the controversy that attaches itself to the overail structure of the Metaphysics. 1 the pRsence of Book r as an integral part of a group of Books, ABï, which establish the basis for a metaphysics, is well attested.2 1t is, indeed, in Books A and B that the direction that Aristotle's thought will take is first revealed as he prepara the pundfor the introduction in r of his own understanding of the nature of reaiity. The opening chapters of Book A establish the template from which the work as a whole will evolve; from the simplest begimings in the sensory perceptions shared by al1 animals. the focus of the search is gradually narrowed to the speculative reasonings of the philosopher on the ultimate principles and causes. In keeping with the ordered and rationai progression of thought that he outlines, Aristotle tums quite naturally to his philosophicai forbears in the expectation of finding in them a gradua1 awakening of an awareness of the first principles of reality . Whereas each individual in a fini te lifespan may uncover on1y a small part of the truth, thought itseIf becornes imrnortal as in the reflections of each generation higher and higher truths are succesively garnered.

Looking back in Book A upon the whole of Helleaic philosophy, Arictotle assumes a vantage point that allows him to analyze the findings of his predecessors from quite a different perspective. When viewed retrospectively what is revealed is a movement in

W .D.Ross. ANiotle's Mefaphysics v. 1. (Oxford: Clarendon Rcss 1924). xiii. Rass, ArLrtotie's Mefaphysiics v. 1, avii-xviii.

1 history, an unfolding of the mind which exposes the ontology of being itself. Under Aristotle's @ding hmd there emerges from what is pariicular aod circumstantial in each of these philosophies a universal and necessary movement of thought from the sensible to the intelligible. It is. Aristotie states rcpeatedly ,the facts themselves that force the rnovemen t of thought in its determineci direction, from the physical to the mathematical to the Piatonic dialectic. and, finail y, through a disentmglement from al1 these chains to the doorway of wisdom itsetf. However, although thought is naturally ordered to its end. koowledge of the divine science. this know ledge is not readil y gasped and so the tme path cannot easily be discemed. The extreme ideaiism of the logïc of the Parmenidean One and the logical atomism of the materialists, Leucippus and Dernocritus, for example. are end-points frorn which Anstotie sees that thought can make no further progres and yet somehow they must remain a part of the picture if a first philosophy is to be possible.

As Aristotle, in Book A, teases apart and extracts the core 'conceptions' on the pnnciples of king and reality fmthe philosophies of those who have preceded him, he uncovers in embryooic form the four causes of the Physics w hich will form a beginninp point for his own investigation in Book T. Al1 men. Aristotle concludes, "seem to seek the causes named in the Physics and we cannot name any beyond thesen (993a10- 12). At the same time there ernerges also from the survey of the history of philosophy a primary dichotomy between the sensible and the intelligible which remains intractable. The battle lines that Plato hirnself drew attention to in the Theaetetus and the Sophisr are still drawn up as the clashes between the Gods of idealism and the Titans of materialism continue unabated. Aristotle recognizes that an impasse has been reached and that the logic of dialectic and participation which Plato employed to address the problem cm be taken no further. What Piato has failed to do. in Aristotle's estimation, is to distinguish what is separable in reality from what is separable in thought. The universal object of thought has been identified by Plato with a universal non-sensible reality which is in tum associated witb true being. Fmm Aristotle's perspective, Plato moves through higher and hipher forms to an abstraction which is beyond their producf failing to recognize that what is needed is a principle within the sensible which will underlie and stabilize contrariety; oUda as a concretion of rnatter and form. With this in mind, a whole new set of negotiations designed to rectify these omissions and effectively reconcile the opposing factions of idealism and materialism will be instituted by Anstde himself in Book T.

In order to solve the problems that face those who would seek to understand the nature of reality it i s first necessary that the difficulties be recognized and then that they be subjected to a thorough examination for "it is not possible to untie a botof which one does not knowR(9%a2.9-30). The npeated derisive comments Aristotle directs at Metissus stem from his contention that Melissus forged ahead with his philosophy oblivious to the dif'culties he was circumventing.3 The difice of his own philosophy, as Aristotle realizes, will ody be as strong as the foundations which support it. The very wonder which drives philosophy towards wisdom is also to be expressed in terms of a deprivation of knowledge, a hptlaiç This deprivation results from the 'knots' which the intellect perceives in its reconstruction of its objects. Without a clear passage to i ts object the intellect ouinot move forward to tmth. What must be exposed if the difficulties are to be overcome is the intemal Ahoç of the object itself and not a ilbyos imposed extemaily by the knower. By identifying and delineating in Book B a set of core problems, &nopiai. which must be addressed if thought is to free itself from bondage, Aristotie seeks at the outset of his investigation to refuse doubt and contention an entry to al1 subsequent development of his thesis. The fint four of these kopim are concemed with the highest principles and causes of wisdom and it is these difficulties which must first be taken inio account, for they detemine both the possibility and the scope of the metaphysical inquiry. This it will be the task of Book r to accompiish. for as Aristotle embarks on his own investigation of npkq @Aoao@ia he will begin by establishing the nature of the science to

To conternporary commentators Book ï has presented two quite disparate faces. On the one band there are those whose attention is focussed on chapters 1-3 and on how the object of first philosophy, as the science of kingqua being, is seen to be pped. Once an initial solution has been proffered to the four hopiai and the 'w hatness', w hic h must embrace within its nature al1 causality and al1 aspects of being qza king irpk Lv. has been identified as substance, the rest of Book r recedes for these investigaton ioto virtual insignificance as a part of any developing argument on the metaphysical nature of reality. "Not content with deciding that Metaphysics ought to study the first principles of dernonstration. Anstotle proceeds actually to discuss hem, and to this the rest of T is devotedn, remarks Ross drily.5 Even ihose who profess the greatest concem with identifying themselves with the integrity and continuity of Anstotle's own thought are not immune from the temptation to i porethe latter part of Book r as lacking in metaphy sical

Sce panicuiariy Aristotlc. Physiccz. L86ad 17. The various conceptions of the nature and origin of the kopiat are discusscd in dctail by Rde. G. Rde. îkConcepf of Fimt Philosophy and the Un@ o/fhe Metaphysics of An'stofk. m. 3. R Cam. 3rd ed. (Albany: SUNY Press, 1980), ûû-98. Ross, An'stotLe1s MetaphysicF v. 1, xvii. irnpoh Hence Owens, while he recognizes that the approach to Anstotle should be through "tryingto divefor the moment the actual pmblems and difficulties"he encountered "taking seriously w hat Anstotle himself took ~eriously,"~nevertheless l imits his assessrnent of the accomplishments of Book r to what is achieved in chapters L -3. the establishment of "the xpk Év character of the principles sought by W~sdom."~Reale, who is at pains to emphasize the organic unity of the Mefaphysics, is likewise content to note ody that "difficulties raised in the second half of the same aporia concemiog the rnanner of the knowledge of the axioms, are resolved in the second part of Book r frorn the fourth c hapter onw ards.

To those who concentrate their investigative efforts on interpreting r4-8 it is the Iogical construction of arguments in support of the principle of non-contradiction and the principle of the exchded middle that dominates Aristotle's interest in Book T. Thus, Barnes is constrained to comment that "[blook Gamma appears to start on the subject itself [i.e. metaphysics 1: it cbaracterizes something which it cdls 'the science of beiug qua king'- and it then engages in a discussion of the principle of non-contradi~tion."~To this, a littie later, he adds that "[v jery roughly speaking, metaphysics, as Book Gamma describes it, is 10pic."~~Indeed, Barnes' position is quite consistent with that most often to be found in ment considerations of the content of r4-8.1 As Halper remarks, "[O Jnthis usual view, r4-8 is consistent with Aristotle's other concems but does not advance his metaphysical investigation." l

In response to what he recognizes to be the limitations of the usual interpretations of the latter part of Book T, Halper argues that the whole purpose of the discussion of non- contradiction is the establishment of essential definition and that to substantiate "[tlhat this is the case is the real result of r4-8."'3 Upton, aiso comrnenting on the inadequacy of a purel y Iogical considedon of Aristotle's discussion of the princi ple of non-contradiction.

J. Owens, The Doctrine of Being in the ANtorefian Metaphysics, 3rd cd. (Toronto: RDntifid Instinitc of Mcdiaeval Studics, 1978). xi- ' Owens, 287. Reale, 136- 1. Bames. 'Meiaphysics,' in Tnr Cwnbridge Cornpunion to Aririotle. ed. J. Barnes (Cambridge: Cambridge UNvcrsity Press, 1993.66. Io Barncs,71-72 Sec, for enamplc, C. Kim. AnSfolIe'SMetaphysics: Btwks T. A MdE Tr~~~~latwnand Notes, 2d d (Oxford: Clarendon Press, 1993); T.H. Irwin, "Aristotie's Discovery of Metaphysics," Review O/ Merophysics, 31 (1977) and J. Lukasiewin, "Arktotlcon the Law of Contradiction," in Micles on Aristotle 3. Mefaphysics, cd. by JI Bames, M. Schofield, and R Sorabji (London: Duckworth, 1979). l2 E Halpr, "Anstoile on the Extenson of Non-Conuadiction.' Hision, of Philosopky Qunrterly. 1 ( lm),369. l3 Halper. 379. emphasizes that there is both a psychological and metaphysical dimension to the account. For Upton. rhat must be seen as most important to the understanding of both the psychological and the rnetaphysical aspect of non-contradiction is Aristotle's conception of potency and actuality. Thus he argues that "Aristotle's metaphysics of potency and actuality ...cornes into play in his understanding of the PNC. at least to the extent that the potency associated with matter, which has a nature such that it can possibly both be and not be something actual,...cari lead one to believe apparent contradictions. " 1.'

The account which follows will investigate afresh the metaphysical argument of Book î from within the context in which it was written, lmking back to its beginnings in the challenge thrown out by Parmenides both to say how it is possible to think and speak being and to explain how non-king can be. Io Plato, this challenge can be seen to resolve itself into an attempt to reconcile the Socratic search for definition with the being of falsity . Now Aristotle, in his tum, will develop in Book r the basis for his own response to the quest to bring king and non-king into a retationship which is comprehensive of both. It is at the very juncture of king and non-being, of definition and change. that Aristotle looks as he establishes in r the basis for a metapeysics of substance in potency and act. presaging the full exposition of these principles that will follow in ZHQ. miethe text of Book r rnust be closely addressecl in the attempt to trace the strands of Arisiotle's thought as it frees itself from successive hopim. this will not of itself be sdficient to provide a coherent picture. To isolate a doctrine frorn the movement of ideas which brought it about, from the feeiings and the intentions which guide it, to consider it as a theorem to be proved, is to replace a living and significant thought by a dead thougkt We can understand a phiIosophica1 notion only by its relation to the whole of which it is a part.15 Aristotle's cryptic references and his frequently terse phrasoology must be understood within the context of positions developed more fully elsewhere, both in his own works. in piirticular the Physics and the De Anima, and also in the Theaetetus of Plato upon w hich he quite clearly draws. Nevertheless, it is not through the imposition of an extemal logos, a preconceived hypothesis, that Book r is to be approached but with the expectation that Aristotle's own unfolding argument will release from within itself the thesis which nurtures and sustains it.

'->T.V. Upton, "Rychologioil and Meiaphysical Dimensions of Non-Contracîiction in Aristotle.' Rrvkw of Meruphysics, 36 ( 1983). 597. É Bréhier, ThP HeIknic Age. trans 1. Thomas (Chicago: University of Chicago Press, 1963). 8. THIS SCIENCE IS AN ONTOLOGY Being has n nature (1003a21-33)

Confident and uncompromising in tenor, the opening statement of Book r offers the promise of a new beginning to the study of the nature of reality. In the wake of a catalogue of seemingIy insrnountable difficulties presented in Book B, the contrast looms large. The extreme scepticism of Book B ernerges oow not as an end in itself but as the opportunity for thought to be liberated from the fetters of a range of mutually contradictory assumptions that have bond the intellect. As it sets out to address the problems presented by the first four hopiai, Book ï provides a fundamental rethinking of the nature and object of philosophic science. However, whereas Book r mada the beginning of Aristotle's own account of the nature of fint philosophy, it is not a beginninp de novo. but one which will draw sustenance not only from the insights of his predecessors but aiso from what has emerged from Aristotle's own investigations of the natural world. Wisdom has been identified in Book A with the science of the first causes and these in their turn have been shown to be the four causes of the Physics w hich are now the established prernises from which the investigation of reality will be launched; for in order to 3a ve an account of anything we must first koow rb 6ià ri nepi Eraiov. I6

Forgotten now, it might seem, is the question raidby the fint bpiaas to how it could "belong to one science to recognize the principles if they are not contrary" (996a20). Through the manner in which the hpiawas presented we have been led to ppresme that because contraries have appeared ta al1 to fulfill the prerequisites of first principles any contenders for first principle must therefore necessarily be contraries. As the four causes are not contraries it has been assumed that it follows eo ipso that they can not be the first ptinciples What has bound the inteilect and haited the progression of thought. Aristotle would argue, is the unquestioned acceptance of a fint prernise which has been insuffcieotly subject to critical evaiuation. When the faul t in this logic is made apparent the way is cleared to question not whether the four causes are contraries but whether they could in some other manner fuIfill the requirements of first principles of wisdom as a singie science. Contraries themselves. as he will make clear in the course of the argument in I2. must be subject to a prior unity which underlies and grounds their opposition and it is of what is p60r that we must seek the first causes.

How the four established first causes cm have a cornrnonalty which allows them to be reduced to a unity. while still being accountable for change. will only becorne apparent as the argument of the Metaphysics is developed. A full resolution of the uxopia must be able to account for the fact that there are unchanging beinp which do not exhibit al1 four causes. For Plato, to have scientific knowledp just is to know these etemal unchanging beings but this wisdom, as Aristotle interprets it. does not encornpass a know ledge of the sensible wodd except in a negative sense. In order to have a single cornprehensive science, unmoved being must be seen to be able in some way to encompas al1 four causes. Whereas the science we seek is not one of the sciences of the Physics but one that goes beyond them and subsumes them to investigate the whole of king and reality. there nevertheless cornes from the Physics an initiai insight into how Aristotle understands this &copia. Clearly in many cases, he there notes. three of the causes (formal, final. efficient) cmbe seen to coincide, kpx~satô& rà rpia eiç év ICOM~ICIÇ-~~

The establishment of the causal limits of reality is the precondition for a science of being. To ascertain causality is at the same time to necessitate that there is something which is correlatively determined through the activity of these same causes; the whar it is of which they are the why it is.

But since we are seeking the first principles and the highest causes, it is clear that these are necessariiy of some nature in virtue of itself . As causes, the four causes must be the principles of something and this, it is cofirmed, in virtue of its own nature. Ultimate causality, in accord with the lirnit it imposes on universal being, must in its hini be associated with what has a definitive nature and is hence an object of science, Aristotle argues Thus it is that he can state with confidence that there is a science of being qua being. The whcu it is is 'being' determined as 'being', rb 6v 6 Gv, to which, in virtue of its own nature, ~a0' aino: belong both its attributes (l003a21-22)and the first principles and highest causes ( 1ûû3a.27-28). And ço, if indeed those seeking the elements of exkting beings were seeking these same prinaples, it is necessary also that the elements of being are not so accidentaiiy but qua being, This science, Aristotle intimates, is the very science towards which the thought of his predecessors was king forced fornard by the tnith. As such. it is not in any accidental way, but by necessity. that these causal principles belong to being and define its nature.

It must be emphasized that the scîence of being qua king is universai and not to be equated with the nature of any partîcular generic science. such as mathematics. which identifies and isolaies a particular aspect of king and examines those causes and attributes which pertain to it qza mathematical (1003a22-Z7). This point will be elaborated further in Book E when Anstotle takes up the question of the subject matter of the science of king qua king once again and reafirms that:

al1 these [particular scîencesl delineate some particular being, some genus, and investigate it, but not concerning king simply, nor qua king, nor do they give any account of the essence. The science which is the object of this investigation, it is quite clearly to be understood. is a science which is universal and transgneric in scope and which treats of king qua king with respect to its esseutid causes and attributes. FROM ONTOLOGY TO OUSIOLOGY: BEING AND UNITY KIPOL "EN

Aristotle bas cleared the pundfor his science with the positing of limit and a definitive nature for being qua being but it remaios to be established whether ihis is of itseIf suffisent to successfully counter Parmenides' challenge that pi) ro WELVTE v&iv T 'éov Bpwvcn.ls Piato too has in a sense a science of being, if this is to be acknuwledged as recognizing being as something which is universal and self identical. However, it is clear to Aristotle that from any conception of being as a genus and univocal it must follow that each kind of king is ontologically equivalent and therefore is in the same way . If being were, in fact, something universal and identical in al1 its manifestations, that is to say univocai and generic. then nothing meaningful could be said for it would not be possible to rnove beyond the principle enclosed within the emptiness of its own self-identity. A principle, to be a pnnciple, must be a principle of something which is other than it It is obvious, therefore, that from these same considerations the 'generic' conception of being qua king which Aristotle has presented in Tl must be %en to be similarly incomplete as an account of redity.

As he successively and systematically lays in place the foundation blocks for a first philosophy in Book T, it is instructive to look forward to Book N and Anstotie's protracted cnticism of Plato and the Academy for an insipiit into the problems with which he is faced. Plato, in particular, Aristotle sees as having corne close to exposing what will be reveaied in r to be the tme nature of reality, and if bis account falls short it does so magnificently. making al1 the more important that its inherent weaknesses be exposed and accounted. Parmenides' challenge to show how there cm be anythiog apart from the One has engendered, as Aristotle understands it, a perceived necessity on the part of those respondiog to dernonstrate that non-being is. It is their tacit acceptance of the archaic (ap~aïr* terms in which Parmenides formulates his chcopia that leads the Platonists to counter-argue fmm the same limiteci perspective, Aristotle comments, and as a result of this they are inevitably led astray. contraries are attributes of an underlying subject whereas a principle, as what is prior. must k the subject of amibution.

But if it is not possible for anything to be pnor to a principle of everything, it must be impossible for the prinaple to be a prinâple as king something other. This would be as if one were to say that white is a prinapte not qua anything else but qun white, but yet that it belongs to the underlying subjed, but is white by king something other. For that [subjectl would be prior. What has to be shown in the context of Book r is how divenity and plurality, 'different' and 'many', exhibit a necessary causal relation to the unity and identity of the principle. being as 'samer and 'one'. Plato with his logic of same and other has sought to address this by distinguishing out fmm being qun king Formai Redities each of which exhibits its owo distinct and unique nature compnsed of king and non-being. However, while Plato bas, in effect, corne to recognize the principle of non-contradiction as the logic operative in the definition and differentiation of reality, he has nowhere satidactody addressed what Aristotle perceives to be his enduring problem of showîng how his Foms are causal, either in their relation to each other, to the sensible particulars, or to the One as their principle. As bas been rightly remarked. "What is lacking is a context within which the indeteminate could 'becorne', and is potentially, the detenninate."20 It is to this end that Aristotle wilI direct his own account.

A further problem confounding Plato's conception of redity, when viewed from Anstotle's perspective, is that ail aspects of being are accorded an equi valent ontologicd reali ty as participants in the universal Form of Beinp. Hence, the question is not simply how existing things are many and diverse but how the multiplicity and divenity in ail the categories of king can be understmd.

And so with the other categories, there is something else that gives pause as to how things are many. For because they are not separable, it is through their underlying subjed becoming many that they are many qualities and quantities. It is absurd, for example, to consider as Plato seems to, that a 'relative' can be a real thing, either poteutially or actmiiy, Aristotie argues, for relatives are least of dl a kind of real object' ( 1088a3435). In fact:

a thing wiI1 be greater or 1sor equal without itself changing if another thing changes in quantity. That Plato was cleariy aware of this difficulty is attestexi by his expressed concems in the Thearetus and the PWo.22 Certainly he recognized there the necessity for postulating a imo~ei~vov,the individual subject, as the unity underlying such differences. However, Aristotle's concern is how there can be a unity for king and the uni ty imposed by the Piatonic dialectic, Aristotle sees, is always an extemal unity, the unity of the dialectician. As such. this uni ty never extends to an exposition of the intrinsic nature of the object i tself but is there for thought aione. The logic of dialectic caught in the dichotomy of king and non-beinp, in which each Forrn is continuaiiy king and not-king what it is, is a science of retreating principles. In the final analysis the logic of Parmenides is not refuted by Plato. ail that is really real, 9nm5 6v. remains the king of the One.

Beiug is oot seif-identical in a plurality (IOO3a33- b22) Plato. as Aristoile understands him. althouph he has clearly distinguished the components of reality, has failed to pspthe significance of siarting from a deterrnination of how the principle itself is in the pincipled? In establishing his universal principles. the pkyrsra y&-, in separation from the particulam, Plato has been unable to develop a science which is cornprehensive of the sensible world. Rather than start with the detemination of the principle as extemal, Anstotle will begin with what is rnost knowable to us, the concrete individual existent, and seek to show how this reveals through its intrinsic nature the universai principle of the whole. Central to the Aristotelian conception of king and to frteing the intellect from the strictures imposed by the first four kopiai is a movement away from the univocal and generic conception of being to the AEyOpva npbq év which Anstde now introduces in I2- By providing that inner connectedness missing from the accounts of the earlier philosophers, the npbs Ëv relationship allows Anstotle to develop a whole new perspective on the nature of being and reality based on the logic of substance.

l Plato, Theueieius, 154B-C. 22 Plato, Pkh. 101A-B. 23 Ross notes that il is to Plato that Anstotle owes " the recognition of the abtract notions of substance. quality, quantity, relation, activity and passivity, The allusions to them occur quite incicientaily in Flato: he never connects them systematicalty. But his tecognition of them as gcneral aspects of rcality must have considerably aided Anstotle's thought-" W. D. Ross, Aristoile, 5th ed (London: Methuen, 1949)..33-23. oGaia. What those who have taken upoo themselves the task of refuting Pannenides have al1 failed to recognize is that being can be said in many ways. I t is in the understanding of how this is so that there lies the key to the dimaotling of Parmenides' strictures and the release from the bpimwhîch cloud the identification and isolation of the object of 'tbis science'.

As Anstotle has noted elsewhere, a term rnay be predicated of different things in more than one ~ay.2~It may be applied univocally, as animal is said to characterize in the same way man, ox, or rat, or it may be found to be equivocally applied as, for instance. to dog and dog star in a purely chance relationship where there is no commonalty of definition. A closer examination of these two ways of speaking reveals, however, that they are insuffiicient to encompass within the bounds of laquage a full conception of the extemal rational order, beinp in al1 its manifestations In between these extremes Aristotle identifies in I2an intemediate relationship and it this xpbç IVway of speaking that is the first step in a solution to the difficulties that have ensued for those who, as he sees it, have given way in face of the logic of Parmenïdes.*s It is the faisity of Parmenides' premise that must fint be exposed and then the conclusions he has incorrectly drawn from this assumption refuted in their tum.

The refutation Lies in that his assumption is false and in that his inferences do not follow. Mis assumption is faise because he judges being to be said simply, whereas it is said in many ways. And his inferences do not follow, because, even if white things alone are taken, and if white has one rneaning, nonetheles white things would be rnany and not one.

While attention is thus drawn in the Physics to the nature of the inadequacy of Parmenides' conception of Being and Unity , it is here in l2 that Aristotie will advance in full his own metaphysicai response. Before moving to consider through an explication of the proper nature of unity how beinp are many, however, he first reiterates his contention that king qrui being is xoMci~&.

24 Aristotle. Car., la3. 25 Physica. 18lai. 26 Physica 186a23-27- Being is said in many ways, but towards one thing and one certain nahm and not equivocally. For clanfication of what he intends by this npOS Ev way of speaking, Aristotle tums immediately to what is most knowable to us in the world of sensory expeneuce. Here it will be noted that in the case of health, for example, there is a common notion. 'heaith'. in relation to which things may be said to be healthy in various different ways Thus. some things will be indicators of hcalth others producers or preservers of health (10a3a34- 10a3b1). None of these things is itsetf 'health' but al1 are related to this one central concept and as such will be the subject of a common science. Similady, it will now be argued, is it the case with respect to kingqua being.

For not only of things spoken of in virhie of one concept is it for one science to investigate, but also of things spoken of in relation to one nature; for these in a certain manner are said in virtue of one concept

Underlyiog and groundiog the nature of reality, for Aristotle, are the categories of being npkËv. As the mind discerns reality it is as ordered and related in the extemality of space and time. The ten categories that Aristotie distinguishes are not, however. merely couvenient linguistic distinctions but a reconsbuction for thought of what is intrinsic to the rational order of sensible king with its principle of motion.

However, in the first place, if being has many senses, sometimes it signifies substance, sometimes quality, sometimes quantity and the other categories. Exhaustive of al1 reality, the ten categories are, for Aristotie, the ultimate abstractions to which king is ordered and as such cohere in their deteminate relationship to one central nature, osaas whais. The study of reality, it is emerging, is the study of okiaas what is primary and existent and it is in the relations between sensible oiwiai. as within the confines of space and time they move and change and are generated and destroyed, that the fabric of the natural world of our experience is comtituted. Some things are said to be because they are substances, others because they are affections of substance, others because they are a proceçs towards substance, or destructions or privations or qualities of substance, or productive or generative of substance, or of thuigs whidi are relative to substance, or negations of one of these things or of substance itsetf. [t is for this reason that we say even of non- king that it is non-being.

Through the npki?v relationshîp the many diverse meanings that king exhibits in a worid of change are ordered in a determinate relation to a prior unity in olioia, substance as the self-identical. Being cannot be spoken of univocally, it is not a genus as Rat0 speaks of it in the Sophist. If king were univocal there could be no meaningful commerce between words and the redity for which words are the signifiers; nothing muld be said other than king is beinp. What &as contributed to the Onopia of the intellect as it strives towards the understanding of a single and comprehensive science of king and reaii ty is this univocal conception of being. Aristotle's xpbg Év ontology is a recognition that intriosic to the nature of being qua king is a distinction of what is prior from what is posterior. Substance is not on an equal footing with the other foms of being: Socrates. musical, pale. and short, are not ail ontologicdly equivalent Take away substance, Socrates as the underlying subject of attribution, the holi~ipwov,and king in a11 its senses ceases to

So that indeed a11 the rest are spoken of with respect to the underlying prirnary substances or are in these underlying substances. And so if there were no primary substances, it would be impossible for anything else to be. Mmary, and comprehensive of all other categories of being, is substance, which is predicated of no other category but is itself the subject of al1 predication. Being per se is substance and al1 other categories of king have their existence only in and through substance. With the establishment of oiwia as the pnmary kind of being, Aristotle cm be seen to have moved hmthe conception of first science as an ontology, the science of king qica being, to an ousiology. Wisdorn, as the highest science. will study king qua king in ternis of what is prior in being which is substance. But everywhere science governs that which is prirnary and on which the other thhgs depend and because of which they are named. And so if thiç is substance, it is of substances that it wili be necessary for the philosopher to have the prinapks and causes.

Being and unity are correlative (lOU3b22- lOO4a2) From a universal and categoricd conception of being. causalfy contained. redity as king qua king has been ordered npiy &v to substance as existent and a this. r6&. As yet, however, there is no account of how substance can be both many and diverse and so consistent with what our senses reveal of the naturaf wortd. As he develops his thought to address this issue, Aristotle will first take into consideration the relation of being to unity. What are most irnmediately knowable to us are the multiplicity of individual objects which constitute the world as we apprehend it These primary substances. which fom the irnrnediate abject of scientific investigation, are to be understood as both what is and what is one, as a concretion of unity and being. In the materiality of the sensible world. timit assumes a physical dimension as substances are 'one', delineated and separated from one another through their existence in place. rb Evi dvat d à6tcnp&tq &miv rivat. OlFEp T& 6vn ai i8ia ~o~~rn@ii 'L* fi &%EX fi 6tavoia ( 1052b 16- 17). To be one is to be undivided, which is king a 'this' and individudy separabte, either in place, or in form, or in thought. Substance cannot be Unity itself as in the immediate self-identity of the abstract One of Parmenides. Nor is Unity somethinp real and existent as Plato and the Pythagoreans before him considered (1053bll-13). For Plato, unity and king are ailowed an independence that is only overcome in the first principle, which alone can be said both to be and be one. The focus, for Anstotle, by contrast, is centred on how beinp can out of itself reveal its own nature for thought It is not possible for this to be accomplished unless it is first possible to say how king is one, for to think unity is to think being.

In generai we must ask what the one is just as indeed what being is as it is not sufficient that this itseif is its nature [to be or to be one].

For those of his predecessors who can be said to have a Abyq everything is constnicted fmm contraries and this, Aristotle claims leaves the necessity of postulating a further principle which will be comprehensive of this contranety. This unifying principle cannot be Unity ,as Plato supposes, for unity and being have no independence from one another. Like being, unity is a universal predicate and together, Anstotle argues. i t is unity and king which detennine substance as both separate and a this.

[Since] being itselt canot be a real thing, as being some one thing apart hmthe many (for it is cornmon to the manyj but is only a predicate, it is clear tha! neither can unity; for being and unity are the most universal of ail predicates. As universal predicates of substance as what is existent, king and unity are therefore correlatives, Anstotle now argues, the presence of the one always implied in the presence of the other ( 10a3b23-24). While their defidiors are different, i t is psibie neither to have king without unity nor unity without being, for refemng being to unity is to Say that something is one and to refer urity to king say that something îs. Hence, 'man1, 'one man' and 'existent man', are i~enticalexpressions, Aristotle concludes, and the doubling of the words adds nothing further (Iû(Bb2629).

The central conception underlying and comlating being and unity is substance, and as histotle now points out:

stiil the substance of each thing is one in no merely accidental way, and in the same way also is just what a certain being 1s; -such king the case there are as many forrns of unity as there of being. What the essence of these is is to be examineci by genericaliy the same science. The science of being qua king is also to be understood, it is now clear, as the science of unity; since unity belongs to king esentially and correlatively and has just as many rneanings as being, A&~E.M 6 ioq* sb 6v rai rb b (1053b25). Through his understanding of a xpbq év relation for unity in concordance with that established for being, Aristotle brings al1 the derivative forms of unity under a central conception of the unity of substance. Study of the various kinds of unity, such as the same, the similar. and the equal. will dl fall withia the xpbç Ev science of unity (10a3b3536). These are not kinds of being, as Plato had supposed, but universal ternis iotrinsic to the nature of king iiself. It will oot be in universals separate and apart fmm individuals that know ledge will be found to reside but in the understanding of what is universally integral to individual things. Wi th the recognition of a xpoS Ev correlati vi ty of unity and being in every category, Anstotie sees that there opens up an avenue for thought from which there can emqe an understanding of the problems of the one and the many which under an older logic of contrariety have now here been satisfhctody resolved. leaving the sensible and the intelligible inevitably apah

Al1 substances fdnnder one science (1004a2-9) The short section from 1004a2-9 raises for examination the question posed earlier as the third hpiaof Book B which inquired whether it is possible that dlsubstances can fa11 under one science (99% 10- l3.9Wa 1S-m. At the heart of the answer to this question is the relationship of the one to the many which Aristotle believes to have been inadequately addressed by al1 of his predecessors. To some commentators this passage has appeared to be out of place at this point in the tex& intermpting the flow of the ongoing discussion on unity and diversity. Alexander and Ross, among others,28 believe it should be placed following directly upon the discussion of the RAdv nature of being. However, ii must be kept in mind that what is primary in the xpiy Év understandiop of both the science of being qua king and of unity qua unity is a conception of substance as whir and is one. What is actually in the fullest sense possessed of both king and unity, in Aristotie's consideration, is substance as the unmoved mover which is totally devoid of materiality and thus, in terms of his own logic, of potentiality. Hence, it is oot illogïcal that Aristotle discuss what is prior and posterior in substance after the discussion of substance as universally characterized by bah king and unity and before rnoving to the discussion of the attributes of sensible substance; that part of substance always in potentiality, never in full possession of its own self-identity. Throughout Book r Anstotle provides timely reminders that the sensible worid is not, for him, what is primary. Viewed in this light, the discussion of the parts of philosophy is adroitly placed between what pertains to a universal science of being and unity and what must be reconciled with this science through an explanation of its nature as potential, the multiplicity and diversity of the sensible.

What is most knowable to us is the sensible world and it is with sensible substances that the inquiry must commence since in the natural world these are prirnary. This must not, however, cause us to lose sight of the fact that the object of our search is not that which is most knowable to us but that which is rnost knowable in itseIf. If theare no substances other than natural substances then wisdom rnust lie with physics as the highest science

Thus Ross asserts that this section. 1M)4a2-9.obviously @breaksthe vain of thought. Alexander wished to insert it at 1ûû3b22; Schweglcr and Natorp, with more probability, to insert it at 1003b19." Ross, Aristotfe's Metapkysics v. 1,S7. For a contnry view which diffa from the one expresscd hem see Reale who believcs thar i t is to gudagainst any misunderstanding that 'there arc as many parts' of philosophy as there arc (identicai, simila.,and so on)" chat Aristotle places this passagc after the discussion of unity and not before. Reale, 120. (lWia27-29). Yet, the very possibility of a science, for Aristotle, depends on reaching back to an unconditional first cause, an ah which is self-explanatory. The nahnal wodd with its principle of motion is an incomplete actuaiity and as such must be deemed deficient, the dependency of its objects on an apXii which is other than the sensible rpvealed in the very instability which marks its presentation to the senses. What determines a science is the nature of its object and the objets of the @xnwoi contain matter and hence are in potency and forever incomplete. This point is further clarified in D where Aristotle goes on to state that nature is oniy one genus of bnng, i?v yap n yhvg roû 6vrq fi @tioiç (1005a34). so that physics, dthough a kind of wisdom, is not the first kind. E

It is on ihis understanding that Anstotle is able io say without presmble that king falls immediatel y into divisions w hich constitute the parts of philosophy .

There are as many parts of philosophy as there are [divisions of] substances. So that it is necesary for there to be among these mmething first and something which follows. For being and unity fa11 immediately into 'genera'. Since. as he has already argued (1ûû3b1617), science has for its object what is primary, then just as what was primary in king qua being was substance, so now what is primary in substance, eiemal substance, must be pnor to sensible substance and as such the proper object of philosophy. The philosopher, on this account, Aristotle says, can be compared to the mathematician, for mathematics similady has parts which may be successively, E*

The placing of mi .iO Ëv in parenthesis is in accord with îhe view subscri bed to by Ross et al. that this passage is misplaced Thus ROSSsays "If we are right in supposing chat 100W-9 should corne before lWb19-36, a reference to d Ev here is out of place and Natorp is nght in excising it. Ross, Arirtotle's Meraphysics v. 1,259. Coaversely, of course, the presence of r6 Ev supports the vicw subscribed to hem rhat this is Aristotle's intended ordcr for the text. 30 The successive parts of mathematin are listed by Ross as fim arithmetic, followed by plane ge~nctry then solid geometry, astronomy, harmonies etc. Ross, Aristotk 's Metaphysics. v. 1. 2.59. For the philosopher is spoken of just as the mathematiaan For indeed this has parts and there is a first and a second science and others succesively in mathernatics.

Reale has noted that, Anstotle malres of two criteria (ra p&v IrpoS Ev %a6È r@ &@el33in order to establish the unity of the Metaphysics."3 l Aithough the hierarchical ordering of substance &@= is cornmonly wnsidered as another example of the rrpk Ëv relationship~~Aristotle clearly intends to distinguish between the two. The idea of a lierarchicd senes in which the lower is taken up into the higher is one that is found also in the De Anim where Tigtire' is first conceived as having a general account which will be cornmon to al1 figures in a series containhg 'triangle' and then, by analogy, 'soul' is argued, to be sirnilady successively ordered.

And it is similar for that concerning figures and those things that have soui- For always what is earlier belongs in succession in potentiality [to that which cornes later], bath in the case of figures and in the case of the ensouled, such that the triangle is in the square, and the nutritive [powerl in the sensory [powerl-

What is of particular simcance in the Dehima account is the insight which it allows into Aristotle's understanding of these hierarchicd relationships Tbat each member of the series belongs 6Mkinui~ei SuMpr to that which is prior, reveals a structureci and ordered relationship in which what is actual at a lower level is contained as a potentiality in an actuality which is pxior to it It is just such an account Aristotle postulates for substance, one in which first philosophy, as the science of np6q o*a, is at the same time fully comprehensive of what is secoodaxy. and successively posterior, eternal sensible and penshable sensible substance as it is identified in Book A ( 1069a30-32). As the nutritive sou1 is contained poteotiaily in the actuality of the sensory sou1 so likewise is sensible substance contained potentially in the actuality of its ah.

l The refercnœ is to fM)SalL-12 He~l~e,as Reale goes on to mtrast these relationships: 'In the firsi case the unity of the science arises fnun the fact thaî ail the rneanings of king are said in relation to an identical nature (A& 'Cilv oiioiav);in the other case, on thc contrary, the unity of ttie science is derived from the fact that the inquiry into the first tcm of a series in a certain sense mbraca it and at the same time the whole series insofar as the series depends on the first tcnn.' Rde, 130. 32 Sec, for example, Owens, 279; G-EL Owen, 'Logic and Metaphysics in Some Earlicr Works of Anstotle,' in Micles on Arisfutie 3. Metaphysia. ai. by J- Barnes, M. SchoficId, and R Sorabji (London: Duckworth, 1979). 20. 33 Aride, De AnUna, 414bZ3-3 1. This is the mswer to the third hpia:the search in the Metaphysics is for an object which is independent. self-relateci, separate, unchangeable and at the same time comphensive of al1 that is other than it, In Book A (980b25ff.). the successive movements of the understanding towards the nature of this object bave been unfurled, as from sensation to memory and through experience to techne. the objects of the sensible world are gradually but surdy stabilized in the intelligible? The principle, as Aristotle understands it, must fiat be reached by distinguishing it from the practicd and productive, but within the theoretical itseif further distinctions are to be discemexi as the end is bmught into oniered relation with the first principle. From a logicai perspective. it is what is there in 'being' itself which defines the divisions of the theoretical sciences Anstotle will argue in Book E Logically, fmm the unchangeabteness of the mathematical and the separability of the objects of physics it is possible to pmject a science which is hipher than and comprehensive of both, rph+i)ioo@ia as ûeok~~~~;the object of which will be etemai, unmoving, and separate. a16iov ai chc1vqm.6~ ai ppidv(I026aIû-16).

The nature of non-king (1004a9-20) With substance now identifieci as the focus nph 8v of unity and being, Anstotle tums for the fint time to an examination of the many. "It is for one science to study opposites, and plurality is opposed to unityn (100QaP10). As he notes elsewhere, and as he would argue Parmenides forgets, it is really in the plurality and diversity of the sensible world that the investigation of the understanding of reality begins. Thus:

Unity is named and explained from its contrary, the indivisible from the divisible, because plurality and the divisible are more perceptible than the indivisible. So that plurality is prior in definition to the indivisible because of the sense perception. Bearing this in mind, Parmenides' stricture debarring any consideration that 'that w hich is not exists' must now be addressed. Where Aristotle sees that Plato has reached forward beyond his predecessors in this regard is in grasping the importance of establishing that beinp and non-being cannot remain diametncally opposed and mutually exclusive principles, as Parmenides portrays thern. but must be bound to one another in a necessary and reciprocal relationship. Through his inclusion of 'othemess', hpov, as one of the jkytara y&q, Plato has recognized a form of non-king which is not absolute. but relative

34 See also in this regard Aristotle, An. Port, Bk. II: Ch19. to that of which it is the non-being.35 Fonn as self-identical reality is at once the sarne as itself and other than everything that it is not: so that 'othemess' as the non-king of the self- identical in this way is. As Aristotle remarks:

He, [Platol means the false and the nature of falsity by non-king ,from which together with being, beings are made many. Plato's accomt isjudged, nevertheles, to be inadequate for it fails to explain other than in metaphorid terms how being and non-king combine to be any one thing. It remains yet to be disclosed from the union of what sort of being and non-king things become many. Aristotle concludes ( 108% 19).

In fomulating bis own response to Parmenides and Plato, Anstotle argues that non-king may be understood to exhibit al1 those categoricai distinctions established aiready for king and unity. Non-king has. in fact, as many senses as has being (1089a16) al1 said with reference to a central conception of substance. Thus there is said to be, for example. the non-being of a man. ro61. or the non-king of the straight, roiovôi ( 1089a 17- 18). It is for this reason we Say that non being is, 610 ai r8 pfi Ôv &ai. pfi dv m~v(lmbll) and not simply as Yalsity' in the way that Mato has proposeci ( lMMCk21).

It is not hmthis sort of non-being [falsityl that beings are generated hmor pass away into. But since non-king in its [various] cases has as many semes as there are categories, and besides this the false and that which is potential is said to be non-being; it is from this [latter] that generation is. A man from what is not a man but is a man potentiaiiy, and white fmm what is not white but white potentially. In place of the absolute non-king envisaged by Parmenides. there cmbe recognized not ody a relative negation of the thing in question, which Plato has identified with falsity, but also a further distinctly Aristotelian and detenninate form of non-being, which is privation. Thus, there is the non-white in the sense of al1 that is other, Erepov. than white but also the non-white as a determinate privation, &prlolç, which is rp6ç n potentially white.

35 Plato, SophLrr. 7578. For negation is the absence of the hg,but in privation there is a certain underlyiying nature in accord with which the the privation is stated. We are able to say that the sarne science will investigate both negation and privation for w hat is reall y under investigation is the one thing (rb Ev) of which the negation or privation is understood to be the case ( lOO4b 12). 1t is for this reason also that i t is psible to assert that the same science will study unity and plurality. Just as it has been found ta be the work of one science to study the various kinds of unity such as 'sarne', 'simila?, 'equal' so too will this science study the opposites, rk~eiwva.of these concepts, 'other'. 'unlike', 'unequai' and whatever else is spoken of in virtue of these or of plurality and unity, icai ka6% néyc~aifi rmà ~uikafi rma Irnîi8oq rai sb Ev (1ûû4a17- 19). Being, uni ty and non-king in al1 their manifestations are ordered both to one another correlatively and to substance ~r&Év.

One science considers being and its attributes (lOO4PZO-lOO5a 18) From an integration of the concepts developed to this point in T;! emerges a response to the fourth anopia, which queried whether it is with substance alone that the investigation must deal or whether it must also take into acmunt the attributes of substance. It is necessary ftrst to make clear, however, that amongst the concepts that fa11 within the scope of the investigation is 'contrariety', for contmiety is a kind of difference and difference a form of otherness, aia@opàyap nçfi Èvavnorr(~,fi SÈ GIUQO~~É~poq (10Wa21-22). In fact, as Aristotle is well aware, a proper understanding of the nature of contranety and its relation to the unity and self-identity of substance is crucial to a solution of the difficulties which have beset earlier thinkers, ail of whom, as he says, make their principles contraries ( 1004b31). It is tbrough a relationship of logical contrariety, Aristotle agrees, that the indetemiinacy of the sensible is first given limi t for thought, for al1 thi ngs are either contraries or are from contraries, irama yap $ évadafi kk Èvavsiov ( 1005a3-4). However, the contraries are not themselves the principles for, as he imrnediately adds, the origins of these contraries are to be found in unity and plurality ,ap~ai 6é r6v évavriov rb Ev rai dfiûq (1005a4-6). None of the categories of being is itself a contrary but through a determinate relation w ith non- king as 'difference' each of the accidental categories admits contrariety ,and in turn, each conhanety can be reduced to a unity which is refemd back npb~ÉV to a primary essential unity in substance.

The science which investigates being qua king investigates being in tems of its comrnon nature and primary manifestation w hich is substance to which are referred in a proportionate and deterrnined manner al1 the attnbutes qua being and qua unity. Once the various senses in which these predicates are expressed have been distinguished they must be further elucidated in ternis of their relation to what is primary in conception. "For some will be so dled by possessing it and some by producing it and others in other such ways" (1004a23-25). To study these attributes in addition to substance itself is the work of a single science (104a32-33). For while there are many ways in which being, unity. and non-king rnay be said:

nevertheIes, it is for one science to to make al1 of them intelligible- For it is not if [these are said] in rnany ways that there are different [sciencesl, but if the definitions are neither with respect to one thing nor referred back to one thing.

What distinguishes the various sciences from one another is not the different senses in which their tenninology is expresseci but the difference in their central concepts Those attributes that belon$ to king qua king and not those limited to particular aspects of king are the pmper objeft of the investigation. Number qw number has its own affections such as oddness and eveness. and other sciences similarly have their particular properties. So. likewise, does the science of king qui being ( 1ûû4b 1@ 16). 1t is not geometry, for exarnple, that studies such things as unity or being or the same or the other (1005a 1 1- 12). It is the concem of the philosopher not the geometer to inquire into whether Socrates and Socrates seated remain the same and what the nature of contrariety is and al1 such related questions ( 1Wb1-4).

Since these are per se affections of unity qua uni9 and of being qua being .but not qua numbers or lines or fire, it is clear that it is for this science to make intelligible both 'what it is' they are and their properties. Where those that have investigated these questions before have gone astray, Anstotle daims, is not by Ieaving the sphere of philosophy but in failing to comprehend the primacy of substance (10WbglO). Only substance is being in its self-identity, a concretion of being and unity ;dl other kinds of being are denvative. related xpo~év to being qua substance. Both didecticians and sophists, it is agreed. examine the same kind of things as the philosopher, for sophistry gives the appearance of studying wisdom and didecticians encompass the whole of dit.in their dialectic (1004blû-20). In neither case, however, are they able to show how the sensible out of its own nature reveals the principle that sustains it. Some advance in thought is to be discerned in dialectic and sophistic in that an extemal unity is imposed on sensible contrariety by the thinking subject as imo~~ipvov. Nevertheless, none of his predecessors, Aristotle maintains, have understood the requkement for a imo~~ip~vovto ground the kingof the sensible.

The necessity of refuting the sophistic position or being trapped within the endless othemess of the sensible is an urgent concem for Plato and Aristotle alike. one voice they condemn the unity invoked by sophistic logic as particular. subjective and unilateral: a perversion of philosophy in which nothing is any one thing and everything has its king through another. However, although the contraries as they are understood in the Platonic dialectic are able to pkdea limit to the endless diversity of matter. they have not stabilized it They have not, in Aristotle's conception, adequately explained how Socrates. pale or tanned, remains Socrates. In order for there to be a science which cau encompass sensible contrariety, thought must begin with something which is a un@ comprehensive of contraries and this cannot be itself a contrary for it must be prior to dl division. Plato understood the nature of the problem when he recognized that although thinking is not a conirary contraries cm be unified in thought He was not able, however, in Aristotle's estimation. to explain contrariety as a derivative fomof being through his logic of participation in which everything is at once the king and non-king of what it essentially is.36 In the final analysis, dialectic, Aristotle says, is merely critical conceming the things

The response to the fourth &copia Aristotle concludes is now evident ( la04a33). The same science will study ali those things into which the dialectician inquires, 'same and other', 'like and unlike', 'contrariety'. 'pnor and posterior' (995b20-21 ) al= 'motion and rest' ( 1004b29). 'pnus', 'species', 'whole' and 'part' ( 1005a 16). These are among the attributes of substance and through substance of being qua king and unity y~wrunity. They are not the attributes of a particular aspect of kingas, for example, kingqua solid or being qr

36 Hence, as has been pointed out 'A thinking through the gencra of king in the Sophisr, for example, sameness and otberness, rest and motion does not permit for an achml knowledge of what is and is one - of finite being- Rather than leading to a knowledge of a principie which is comprehensive of contnricty and divcrsity i t leads to a principle of Uni ty which is an abstraction beyond division.' D.K. HO~ISC,"Why is Plato Omittcd hmCriticai Examinaiion in Metaphysics Book r ?", papcr prescntcd LO thc Classical Association of Canada meeting, 1993.4. And so it is clear that a single science investigates king qua being and its attribu tes q UP king and that this same science examines not ody substances but also their attributes both those that have been mentioned and 'priof and 'posterior' and 'genus' and 'species' and 'whoie' and 'part' and the rest of this sort of thing. The nature of that underlying unity which is substance has yet to be revealed and will become the focus of an extended examination in the middle books of the Metaphyrics. Here in r Anstotie offers odya passing reflection on the significance of the logic of potentiality and actuality to a proper understanding of non-being; one w hich w il1 allow him to succeed where he sees Plato to have failed. Fonn and matter, it will later be seen. are not opping principles of king and non-king held in an unstable association, but tendencies to unity, moments in a single activity which is substance. Unlike the p&pora ykvq of Plato, none of Anstotle's categorks are contraries. The accidentai categones, contentless themselves, stand in an abstract fomal retationship to any of the number of contrarieties belonginp to their particular genus, the dividedness of the contraries related to an underlying unity in the category of king which admits them. Self-relation is there in the fomi and the division in the content it admits, as quality, for example, will admit the hot and the cold. Thus, the endless diversity of the sensible continuum, encompassecl and first subject to the limit of contrariety in the categories, is ultimately reducible xpk &v to the unity and identity of the primary category of substance.

From the argument of ï2 has emerged a new basis for the understanding of reali ty; w hile the pk'ytsra yÉw of Plato are retained they have been recast, formed from a qui te different mould. In beginning his own response to Parmenides' challenge, Anstotle has established the correlativity of 'being' and 'unity' which he sees must be the bisfor any science since without this there can be no definition. Reality in its pluraiity and diversity has been discemed to be ordered to a central notion of ou&a, manifesting itself concretely as whar is and is one. At the same time, the charactenzation of non-king not merel y as relative negation in a logic of 'same' and 'othef but as detennined by an underlying nature, has allowed Aristotle to establish a basis for the consideration of 'motion' and 'rest' in an intepi fomulation of potentiaiity and acruality which will ailow the many to be brought into a meaningfd relation to the one. That the sensible world is existent and comprised of 'beings', objects which are physically separable and in that sense 'unities' is what is most knowable to us and from there we must begin. Substance is both principle and cause and the only answer that can be given to those who ask such questions as 'why man is man' is because each thing is inseparable from itself, and its being one is just this ( 1041a18-19). FROM OUSIOLOGY TO AITIOLOGY

As Aristotle enters I3, he is no longer concerneci with king qua king in any Parmenidean or Platonic sense but with primary substances, the objects revealed to us through our sensory perceptions as both separate and individuated. Hence, what must now be examined is not that ultimate disjunctive polarity of king and non-being over which the thought of bis predecessors has unsucccessfully stumbled but rather the relation of substance ro ail that it is not, Amidst the flux of the sensible world substance is sustained in its own identity thmugh a relationship to what is other thau it. Each thing both is and is known ody through the other which delirnits and defines it as both a 'this' and a 'such'. Through an understanding of the nature of king and unity it has been shown how the sensible world is comprised of a multiplicity of things w hich are both separate and 'this'. r6&, but as yet the diversity of their natures as 'such' or ro6~n rernains unaccounted. It is to the question of fornial causality, as the prerequisite for the establishment of an essentiai nature, that Aristotie now directs his attention. Only once this essential causality has been established will it be possible to explain how the variety of different sensible things which Our senses reveal can be known. That there is a sensible world populated by diverse Ends of existent things Anstotle believes to be self-evident and therefore beyond question, as he will later indicate in his response to Rotagoras (10 1 1b4-7).

From an ousiology with sensible substance as hou~ipmovthe focus of the search for the object of the first science has been sharpened to reveal it as an aitiology in which substance as formal cause will ernerge as the principle sustaining the divenity of the sensible. As a prerequisite to the investigation of formal causdity there must first be an identification of the operative logic of substance and this it will be the purpose of T1 to accomplish. There are, Aristotle declares, certain fundamenial axiorns which are universal truths applicable to being qua being and, as he now postulaies in respoose to the question raised by the second chpia, it is evident that it is the same science that studies both substance and these logïcal axiorns which will be identified with the principle of non-contradiction (PNC)and the principle of the excluded middle (PEM).

For these truths hoid good for everything that is and not for any special genus apart from the others. But al1 use these because they are [truthsl of being qua king, and each genus has being. Although they are used by those studying the special sciences, the commonalty of these principles to al1 science makes them the proper concem of the philosopher who studies king qua king. It is not for the geometer or the anthmetician or even the physicist to comment on the tnith or falsity of these laws although. indeed. Aristotle remarks. some natural phîlosophers have attempted to do so in the mistaken assumption that the natural wodd is constitutive of the w hole of reality .

But since there is one kuid of thinker who is above even the natural philosopher (for nature is only one particular genus of being), the discussion of these tniths will belong to him whose inquiry is universal and deals with primary substance. Physics is certainly a kind of wisdorn but it is not qua being that physics studies its objects but qua moving. Since, as Aristode has already argued37 there must be, grounding the sensible, a first cause of motion itseself unmovable, physics cannot be comprehensive of al1 reality and therefore cannot be the xphq @[email protected] falls, therefore. within the province of the philosopher and not the physicist t9 undertake not only the study of substance and its attributes but also the inquiry into the logical principles.

But he w ho knows best about eadi genus must be able to sta te the most certain principles of his subject, so that he whose subject is existing things qua existing things must be able to state the most certain princïples of al1 things. This is the philosopher. The principle to be investigated must be the most certain. bf3atmaq, best known, ymprpwsaqv, and unhypothetical, ~6~~0v,of al1 ( lûWb I 1- 14). This, Anstotle States, is:

that the same attribute ca~otat the same time belong and not belong to the same subject and in the same respect. The most unhypotheticd of dl principles. the unmovable first cause and ground of the sensible has now been identified with both substance and the operational activity of the principle of non-~ontradiction?~Clearly the iwo must be understood to codesce so that

Physica. 242.a19 ff; Metaphyvsia. 994a6-8. Lukasiewicz, points out that modern symbdic logic has identified 'simplcr and 'more evident' principles which might be treated in preferençe to the Law of Contradiction as ul tirnate and unprovabtc the causal activity of substance will be through the binary logic of non-contradiction, the logic of 'same' and 'other'. The PNC,as Aristotle has already made quite clear ( 1ûûSa22- 25), is a universal principle of reality and so must be applicable not only to sensible substance and i ts accidental amibutes but also in some marner to npkq okiaas the upXi( of the sensible. Ansotle does not hirnself specifically address this issue but the logic by w hich i t may be uaderstood can be detemined. The first principle of reality as a transcendent unity is, for Aristotle, a seif-determinhg priaciple of formai ideutity, v6qo1~ v6queq v6qcnç (1074b34). In the absence of any 'othef against which ihis self- determining activity can be recopized as operative throuph its explicit expression. the logic of both the PNC and the PEM remains irnplici t to the principle. In the finai anal ysis these fundamental axioms are not separate principles but aspects of a single principle of identity. In the realm of the sensible. the seif-determining activity of furmal cause. as a principle of finite identity, is constitutive to each of the mynad of pnmary substances and the logic of the PNC and PEM becornes explicit as sensible substances are ordered and divided as 'same' and 'other'.

As Aristotle first propounds it the PNC is a principle of 'being' for aiways the beginning must be made from what is. If king is to be knowo, however, thought must be structured so as to pattern itself in accord with the implicit ratiooality of the sensible worid. Thus. the laws of king will be the laws for thought and it is the primary principles, the axioms of the science of being qua being, which are the Iaws underlying the human thought process. Reality, for Anstotle, opens up to thought as it is, the logical parailehg the ontological. "For 'true' and 5s' are similarly orderedWs9and "to say of what is that it is and of what is not that it is not, is true" (101 Lb26-27). In order for anyone to corne to know anything at al1 (T@ hôvyvopicovn) he must first have an implicit understanding of the PNC for this principle is prior to any hurnan knowinp; it is not science but intuitive reason that pspsthe PNC as a primary premise.40

laws in particular thcre is the Princip& o/l&nfity: A property belongs to that object to which it bclongs-" Lukasiewicz, 54. indeed, this may be so if al1 that is of conccrn is the establishment of ii hicrarchy of ernpty lo@dabstractions devoid of application to dity, but for Anstotle this is far from king the case. As will cmerge during the course of the argumcnt in Book r, Aristotle certainly understands 77w of ldentity. as a pnnciple of finite investigation, to be the causal principle of substancc as it manifests itseif in the sensible as essence. Howcver, sensible substance uniiscif bc defincd and dei ineared on1y in relation to ail that i t is naand this in accord with Tlre Pn'ncipie of Non- Contradicrion which is thus for Aristotle logicaliy prior. 39 ARstotfe, Anal. Prim, 52a35. 4Q Anal. Pm., 100b12-13. And what it is necesary to know for anyone knowing anything at ail he must have corne posseshg already. The intellectual soul, as it is described in the De Anima, is the place of the foms, rkq ei60v, and Plato is lauded for speaking of sou1 in this wayY The thinking sou1 has the capacity to know dl things, Aristotle says, but before it thinks, aithough poientially dlof is through the activity of fornial cause as PNC that this potentiality can be understood to be actualized. Knowledge begins in sense disceniment, 6ijvaprç ~cprnicil,~~and through experieoce the universal cornes as a whole to rest, ip?pqacxç, in the soul, TOU Evxnapà rà irowwhere its essential nature is intuitively grasped in a logic of 'samer and 'othef. in the way Aristotle describes this pmess Rato's domine of recoliection is brought to rnind, for he speaks not of a corning to know through abstraction from sense data but of a coming to itself for soul in its recognition and retum to its source in vo*.

Such as in battre when a retreat has occurred when one makes a stand another dws so, then another, until there is a return to the original postion-

The response to Parmenides challenge to show how being cm be thought and spokeo requires an exposition of the principles of the understanding which will allow the distinction of 'what is' from 'what it is not'. What is' in the primary sense, for Aristotle, is substance for al1 king is to be relateci n& Hv to a central nature in substance. Nevertheless, it is evident, as Aristotle further defines the PNC.that i ts range of operation is not to be lirnited to substance as the self-identicai but must be extended to be fully inclusive of al1 attribution, whether essential or accidental, so that the whole of the sensible wodd is bound by the lirnits of its Iogic. Thus, he maintains that:

it is impossible that contrary attributes should belong at the same the to the same subjed (the usuai qualifications must be presupposed in this prernise too).

De Anho. 429arl-28. 42 D, Anha. 42-29. 43 hi.POSI., 99b35-36. Anal. Post, 100a67. Ross notes thai this passage is rrminiscent of Plaîo's Pihoodo %b EK S pwq~ mi AufWcqs ~6 ip~pîv,KM~ mika ykpdeol h&qvV W.D. Ras, ArtSrotle's Pnor and Posterior Adytics (Oxford: Clarendon Pras, 1949). 6n. 35 Anai. Post.. 100a12-13. Of course, in extending with this statement an actd reality to the w hole of sensible nature Aristde has in a way removed fmm the natural the very rnainspring of its existence w hich is motion. since motion is defined as an incomplete actuality and it is as actual that the PNC is applicable. Thus, for the purposes of Book T, in which the central problem is that of definition, the wortd may be supposed as a mries of instantiations. While Aristotle will be cooscious throughout the latter part of r of the problem of change it will only be once the dynarnic nature of substance has been fulIy revealed, through the exploration of potentiality and actuality in Book 8, that he will be able to allow motion to freety reenter the world while at the same tirne retaining his hard-won victory over those who would deny any real being to the sensible. If the sensible is to be known it must be subject to definition and if fint philosophy is to be comprehensive there must be a way in which the vanabiiity of the individual can be brought into a stable relationship with the universality of the form. FORMAL CAUSE: TISE LOGIC OF SAME AND OTHER

Since definition must be ai the hart of any understanding, it is not surprising that Aristotle's argument is now focussed on establishing that constitutive to sensible substances is their essential nature. Substance. already a 'this' must be seen to be a 'such' and for this to be the case it must be shown that it is characterized by forma1 cause as a pnnciple of finite identity. Buttressing and determing this logic of identity and ultimateiy reducible to it are the PNC and the PEM. The exposition of the Iogical principles of the understanding in ï4 will be found to be specifically designeci to throw into relief substance as rb ri fiv &m. Thus, it follows that Xa thing has an essence, a finite identity, it must at the sarne thebe said that it cmot bthbe and not be' (PNC) and it must 'either be or oot ber (PEM ) that essential unity which is the subject of the definition. Those who would reject the PNC or the PEM, thereby eliminating essential definition. deny in so doing that there can be any stable finitude for thought. Such opponents have ken identifid and before Aristotie can progress to an examination of the nature of &a itself he must first address and refute their claims Ciassifieci as Heracliteans are those who, wittingly or unwittingly, ~jectthe PNC insisting upon the position that al1 contrarieties are tme ai the same tirne. From an opposite perspective &se the claims of those who, like Anaxagoras, can be said to reject the PEM. by claiming that everything is rnixed together and 'neither is nor is not' any one thing.

One thing Aristotle makes quite clear before the discussion commences is that the PNC is not subject to dernonstratioo. Indeed, it would be foolish to assert that it should be for indemonstrability is what defines it as a prirnary axiorn.46 It shows a want of education on the part of anyone who fails to recognize that this must be the case.

For it is uneducated not to recognize for which things it is necesssary to seek demonstration and for which it is not necessary. For, it is impossible there be a demonstration of absolutely everything (for there would be an infinite regress, so that there wodd still be no demonstration). Such 'proofs' of the PNC as Aristotle may appear to offer can only loosely be so-dled. More properly they are requests of an opponent to attempt to refute this law and in so doing establish a basis for their own contention that things can be 'so and not so.' The PNC is

4"teial. Post., 10b5 ff. not the immediate object of the investigation in r. Nevertheless. as the most fundamentai priociple for the stmcturing of both king ancf thought in the sensible, it is the weapon to be deployed in establishing the authonty of substance as the self-identical. If the Aristotelian position is to be sustained it must withstand any attack that can be mounted agaiost it-

Those who assert that everything can be said simultaneously to be both 'so and not so' inciude, "among others, many writers about naturew( 10W-3) who denve this opinion from their interpretation of the position of Heraclitus. What they fail to recognize is both the inadequacy of the reasoning that results in such an assertion and the absurdities which it necessarily must generate. Whereas it is, of course, possible to say anything, what Aristotle will argue is that a proper logical analysis will show that it is not possible to truly hold the professed belief that things can be unqualifiedly 'so and not so'.

It is impossible for any one to believe the same ihing to be and not be, as some think Heraclitus says. For what a man says he does not necessarily believe. The series of arguments that Aristotie now mounts against the Heraclitean position have mutinely been interpieteci as strictly a logical defence of the PNC and even as purporteci proofs of this principle,47 despite Anstotle's specific and explicit rejection of this latter as a possibility ( 1006aS-9). Chapters 48 of Book r have consistent1y been uprooted from their context in the Metaphysics and subjected to extensive cntical analysis from the singular perspective of their logical component. Indeed, as has been aptly remarked, this section of the Metaphysics is usuail y regarded as "merely an island of logic in a sea of metaphy~ics.~~When examinecl from this perspective alone, wrenched from their context and reduced to the sterility and isolation of the logical. it is perhaps not unsurprising that Aristotle's arguments in ï4 appear to some an ill-considered and puzzling assortment. ancient camion ripe for predation by modem symbolic logic.

In the context of the Anstotelian metaphysics, the PNC canot be considerd in isolation from its relation to the king whose reality it articulates: simply put, without the PNC there is no king and without being no PNC. In his examination of the logic of contradiction in Book T,Aristotle oever waivers €rom his stated purpose. This is not a study of logic qua logic but remains throughout an investigation of being. There is a science of being qua beinp conceming which we must seek the causes, the 'why it is' of 'what it is'. Anstotle

47 Epimmizing this appmh are the works Qtcd carlier by Kirwan, Irwin, and Lukasicwic~ 48 Halpr, 369. announced in ïl. Now, however, in light of the discussion in m. the scope of the investigation can be refineci. Beiog and unity have been found to be correlative. 'what is and is one'. making possible definition and at the heart of definition is substance. The science of being has been redefined as a science of substance and the Iogical contraries. It is hmthis perspective that Anstotle will advance his argument against the daims of opponents who would deny that then exists any stable finitude to be known by thougbt.

A. The PNC as an ontological prinaple (1006a18-1008a2~ This Yirst proof so-called of the PNC. it will be established, has been carefuily crafted by Aristotle to define the essentid nature of sensible substance with reference to the PNC as causal principle. While the focus throughout is kept on being, the inherent logic operative is that of non-contradiction. There is no oeed to start the discussion by requesting an opponent say something 'is' or 'is not'; indeed, Aristotle observes. this would be to beg the question. However, it is necessary to take as a starting point that a tem signifies something both to the one who utters it and to the one who hears it ( lOO6a 1%2 1). In acceding to this our opponent will, while denying that there can be anything that is definite, at the same tirne, by his very utterance, affirm what he seeks to refute, fi5q yap TL E

Being as the subject of definition (1006a29-1006b34) The ensuing argument is developed in a series of steps as Aristotle moves successively to estabtish the acceptance of a primary and unmediated comection between extemal reality and the mental conceptions it invokes in humans. Thus Aristotle says in tum: 1. Say something which signifies (1 006621). 2. A name signifies something to be or not to be (1006a29-30)F 3. 'Man'. a name, signifies one thiog ( 1006a3 1). 4. It is not possible to be and not be the same thinp (1006b18). 5. The point is not whether the same thing can be and not be man in name

49 Tberc are a numkr of vajiant translations ofrrpcihv pÈv ooUv MAnv ojg miin5 y' miro tih1û& Gn qpaiwr 70 &opa 'IO &VQL 4 pfi ~ivm'10% ( 1O06aB-30). RmfolIowing A1e.der and Thomas translates this passage as "First then this at Ictst is obviously true. that the word 'ber or 'not be' has a definite meaning'". W.D.Ross, ArLrtutle's Me~aphysics v. 1, 269 note 1. 38, Whlc Ross et. al, lay emphasis on the existentid meaning of the vch 'to be' it is hard to see that this would add significantly to the argument Indeed, Aristotlc. considering his dierasseriion that 'being man' and 'man' are the same thing (1003b2627), would hardly fwl it neccssary to make such a point. 1t is nevcr a question for Aristotle as to wheüier there is an exted reality that can be said to 'bel. His concern is whether or not anythmg can be said to be one thing. Kirwan, in his recent commentq offcrs an aiternate rcading "First, thcn, it is plain that this at least is itselr true. that the name signifies to be or not to be this particular thing.' Kirwan, 9. Considering the progression of Aristotle's thought Kirwan's translation seems more apm- but whether it can be so in fact, ( 1006b22). The focus from the outset is on king for it seems that if the opponent so much as names anything then irnplicitiy this signifies that it is or is not a definite thing ( 1006a29-30). Having established this as the indisputable pundfrom w hich the argument cmbegin, Aristode proceeds to examine a specific example which will illustrate his point. A word, 'mm', for example. has a mûaning which is refleaive of a definition found embodied in a paaicular thing. It is not necessary for Anstotie to postulate, however, that there be ody a single unique definition associated with a single concept. While a definition is what is necessary to delineate a species, there is no requirement that it be sufficient to characterize to the full the species' essential nature. Hence the definition for man Anstotle chooses here is 'biped animal' whereas elsewhere he will use the definition 'rational animal'.50

The formula of a definition for a sensible substance is always comprised of the highest genus and an ultimate distinguishing differentia; however, the actual differentia arrived at depends on the rnethod of division employed.' 1 The point is that if someone were to argue that there are other ways man cm be defined this does not make any difference to the validity of Aristotle's argument. What is of impoitance hem is that although many vdid definitions may be possible for any one thing there canot be an unlimited number. For if:

one were to say that the word has an infinite number of meanings obviousiy reasoning would be impossible; Cor not to have one meaning is to have no meaning. The name then sianifles a particular kind of being which is defined by a fomula, or limited number of formulae, which characterize it and delineate it for thought. From this it follows that it is oot possible "that 'to be for a man' should signify what 'not to be for a man' signifies" (1006b 13- 14). It is important to observe that what is king examined here is, in fact, the essential nature of man. Thus, we are not considering attributes which belong to man accidentally, that is to say those signifying something about the individual qua i ndividual-

Since on that assumption even 'musical' and 'white' and 'man' would signify one thing so al1 things wiil be one for they will be synonymous.

50 1t is qui te clcar fmtbe De Anhand the Nicomaciiem Et..ihat Aristotle considm rationai aciivity is what uniquely and essemtiaily characterizes man l This is argued fully by Aristolle in ki.Z 12. now be concluded that if something is a biped animal it is necessarily a man and convenely if it is not a biped animal it is necessaîly not a man. for under the terms of the definition this is what the words 'man'and hot-man' signify. Thus it is impossible that the same thing to be affinned and negated truly as a man.

Being as substance and essence (1007a9-1007b18) What is emerging from the argument under the auspices of an examination of the PNC is that implicit to meaningful discourse is a notion of ouoia as an inherent principle of finite identity. The request that our opponent 'say something meaningful' has moved from a consideration of 'man'as a signifier to what 'man' signifies essentially, 'biped animal'. If it cm be agreed, as has been argued ( 1006b 16- 19), that signifying something about one thing, for instance, Socrates is 'white' and 'musical', is not the same as having one meaning, Socrates is a man. which is to say he is a biped animal. then it becomes clear that to say something significant is to Say something which is essentially and not accidentally attri butable.

For nothing prevents the same thing king both a man and white and a thousand other things: but nevertheless if one were to ask whether it is true to Say a man to be this or not, the answer ought to signify one thing and ought not to add that it is also white and Iarge. In any case. Aristotie says, if anyone were going to add accidentai atbibutes they should enurnerate al1 of them, which clearly is impossible, or none at al1 ( l006al517). To do otherwise, he must conclude. wouId be to answer arbitrarily. Nor, for sirnilar reasons, should anyone answer in response to the query whether something is a man "Yesand not- man also." This would still be the case if it were really so that the same thing was man and not-man. One should respond meaningfully to the question asked, but to append what is accidental is to include what is not meaningful. Thus, having granted that the thing is 'man'it is neither relevant nor appropriate to add al1 the things a man either is or is not accidentally. including 'not-man'. If anyone does this then there is no conversing with hirn, 06 &~E'I;~I,Aristotle asserts ( 1007a.20).

To say anything at dl that is meaningful about a thing is to signify, whether directly or indirectly. an essential nature. This has ken iilustrated for 'man' and the argument has been further refined to reveal substance as essence, pure and unadulterated. divested of al1 its accidental predication, clearly and unequivocably delineated from ail that it is not- The full import of what has developed will now be brought to light.

For there was one thing signifieci and this was the substance of something. But to signify the substance is nothing other than [to signifyl the essence for this thing. But if, for this thing, being essentialiy a man [is the same as1 either to be essentially a not-man or essentiaily not to be a man, [its essence1 will be something other [than what it isl. In signifyinp substance as the essence of what it is to be such a thing, iroiov n. it cannot not be such a thing and still retain the same essence. It is now possible to state quite categorically that those who would deny the PNC and daim that thïngs can be both 'so and not so':

eliminate substance and essence. For they must say al1 attributs are accidents, and that there is no such thing as just what it is for a man to be or for an animal. The consequences that necessarily follow if substance and essence are eliminated must now be coafronted If dlattributes are accidental then they can be said to be on an ontological par. From this it follows that there will be nothing that is p60r and thus nothing will have an essential nature or be any one thing for there will be no undedying subject in w hich these accidents are inherent. What an examination of the unfolding of reality to thought in his predecessors has revealed for Aristotle is that if first philosophy is to be fully comprehensive of the sensible then there must be a Vnor~ipvov,something inherent that underiies and stabilizes the finite: tbis Aristotie has determined to be substance and substance is characterized by its constitutive essence, .rb ri fiv &var.

Sensible substances are charactenzed, for Aristotle. both by their physical 'separability' and their 'thisness', mernbers of a species being distinguishable one from the other as individuals by a particular combination of accidental attributes. Thus. Socfates. small, pale and unmusical is a man but is distinguishable and separable from Callias who is tall, dark and musical, but also a man. However, although perceptible as an individual 'thk' (r66e), primary substances as Aristotle narnes them53 are not knowable as such. It is

- - 53 Cat.. 3b10-13 integral to Anstotle's understanding of 'thisness' that i t is characterized by the presence within it of an underl ying essential nature, a 'such' (notov TI). or secondary substance which renders it knowable" Once this essential conception of man, or any other underlying common notion which allows the classification of individuals into species. is removed, there is no basis for definition for it is impossible to have a defilnition of the individual.

For di things that we corne to know, we corne to know in so far as they have sorne unity and identity, and in so far as some attribute belongs to them universally. Those who eliminate substance and essence must. Aristotie says, accept the consequence that follows which is that al1 attributes are accidentai. If, as Aristotle's Heraclitean opponents would claim. everything both 'is and is not' then kinga biped animal' and 'not beinp a biped animal' would be equaily 'essentially' predicable of man. Hence the stability of the defini tion of man would be destroyed. as indeed would be an y other defini tion which might be proposed, for being essentially a man will be the same as king essentially a not- man or not kinga man ( 1007a28). The only logical conclusion to be anived at is that there can be no definition of anything. As far as Anstotle is concemed. this is the cnin of the argument. Those who would deny the PNC must therefore perforce deny essence. In removing essence, the 'such', they at the same time destroy, ipso fmo. primary substance as the existent concrete individual 'this'. Hence the sensible world is not only no longer knowable but, as far as Aristotle is coocemed, it thereby ceases to exist.

Two possible alternative positions can be envisaged to present themselves to those who would deny substance its essential nature, neither of which can be considered to be acceptable to Aristotle. Thus. on the one hand, it might be concluded that each individual 'primary substance' is a discontinuous parcel of matter comprised of its own fluctuating battery of accidents, separate but unknowable in any objective sense. If this is so then it is still not possible to 'say something meaningful' and, as has become clear, this cannoi be a consideration for Aristotle. It is possible also to argue. on the other hand, that whereas there are reco-nizable 'essences' which allow the practical classification of primary substances into species these are subject to variation and hence do not give nse to discrete and discontinuous specific essences in the strict Aristotelian sense.55 While this point is

'j Car,. 3b17-18. 55 It was the recognition, fdlowing rhc work of Darwin and Wallace, that spesvariability dmin Taci occur tbai led to the abruidonment of the Aristotelian notion of fixed specics. not raised in the Metuphysics, Aristotle is quite expiicit on the matter elsewhere; substance, he asserts, is just what it is, never more never less.

For example, the same substance, man, will not be more or les man either when compared with himself [at some other tirne] or another. Aristotte's position is the logicd outcorne of bis own world view. When faced with the seemingly endless variety of sensible substance the choice is clear. either the sensible wodd is one of randornness and chaos, as the Heracliteans suppose, or it is implicitly rational and ordered and hence knowabte. For Aristotle, it is self-evident that the latter is the case, everything exists, he says, because of the ratio inherent in it (993a2û). Reality has a structure which unfolds inexorably to the logic of our understanding and it is through the operation of the PNC that the endless Merence of the sensible reveais its essential order. The sensible world aithough indubitably characterized by a pnncipie of motion and change has its own iuherent stability, the clearest reflection of which is to be found in the unchanging and etemal conception of species within which the individuals in endless cycle ceaselessl y come to be and pasaway.

To say that everything is accidentai is ludicrous. as is now obvious. It is, in effect, as far as Aristotle is concemed, to deny any sensible existence whatsoever and to do away with king in al1 its foms which is to fly in the face of common sense. That there is an objective reality that out senses reveal to us is. to Aristotie, self-evident and it is this primary premise that grounds dl our investigations.S7 The accidentai always implies predication of a subject but even if one accident were predicable of another, as subject accidentally. unless a primary subject of w hich something was essentially predicated was eventuall y reached thewould be an infinite reges, for the predication would go on ad i~fi~turn( 107b 1 ). In fact, accidents cannot be predicated of accidents, for instance:

1 may say that the white is musical and the latter is white, only because both are accidental to man. Unless inherent in a subject, aüributes of w hatever category have no sensible reali ty and remain abstractions. There must, Aristotle concludes: be something which denotes substance. And if this is so, it has been shown that it is impossible for contradictones to be predicated simultaneously.

Being as potential (1007b18-1008a2) Those who say that contradictions are true of the same thing at the same time are in effect. Aristotle says, eliminating ail distinctions so that they make everything one. This is true. he asserts, not only of the Heracliteans who claim that everything is in flux so that it both 'is and is not', but of al1 those whose views deny any redity to essence and substance and ihis must include the followers of Rotagoras and Anaxagoras. In this so cailed 'second proof' of the PNC Aristotle will be seen to pather the views of al1 his opponents into a common position in which they can be seen. by eliminating definition, to reduce al1 king to an indeterminacy.

The Rotagoreans assert that everything is as i t appears to a perceiving subject so that from this it follows that the same object when perceived simultaneously by different subjects can be said tmly to have contradictory qualities. Thus, Anstotle concludes they must accept

it seems to anyone that man is not a trireme, evidently he is not a trireme; so that he aiso is [a triremel, if, indeed, the contradictory statement is true. From the position of Protagoras, we must conclude that an object which can appear simultaneously to be two contradictory states cmhave no essential king and by extrapolation we can say that it both is 'al1 that is not' and 'al1 that is'. Such a position ladsinevitably to the doctrine of Anaxagoras for whom ail things are mixed together and nothing is any one thing, there in its own self-identity. Thus. Aristotle says, that while thinking they are discussing king, the arguments of ail these opponenis move only in the shadowy and indeterminate realm of non-beiog: ~6yàp 6uv&p~~6v mi p* EVCEAE- HUTO &o~~CFTOV€=v ( t ûû7b28-29). for it is that which exists potentially and not in complete reality that is indetermina te. The ultimate consequenees of adopting such a position are now pressed home. If one is willing to predicate of somethiog that most contradictory to it. which is to Say the very negation of itself, as when one says of a man that he both is a man and is at the same time not a man, then how can one say other than he is not a tnreme, or not a wdl, or not everything else for that matter. Since he is not al1 these things then, of course. he also is al1 these things for this follows frorn the assertion that dl contradictory statements are tme of a subject at any one time. In other words, while nothing is any one ihing, essentially, yet everything is at one in its indeterminacy.

The argument has now reached a critical juncture for what has emerged as cornmon to the position of al1 opponents. from Aristotle's perspective. is an understanding of non-being which, while it is completely indeterminate, is not that absolute non-being of Parmenides which offen no avenue of escape for thought As if to emphasize the significance of this conclusion, Aristotle has idroduced at this point his ow n powerful technical vocabulary of iS6vaprq and évdk~~ia( 1007b28) anticipating the manner in which he will later take up the extrerne negativi ty of his opponents and order it to a determinate end Against al1 these opponents. now found to encompass not simply the Heracliteans but aiso the followen of Rotagoras and Anaxagoras, the object has ken to establish the essential nature of substance by exposing the reductio ad absurdm that must surely ensue from their clai m that everything is both 'so and not so' necessitating as it does the outright rejection of the PNC. There has been no incontrovertible proof of the universality of the PNC for this is obviated by its very nature as a primary causal principle. Nevertheless, Aristotle would argue that in so far as each individual sensible substance cmbe said io be definable essentially it dernonstrates formal cause in act through the logic of the PNC.

B. The PNC as an epistemological principle (1008a2- 1009a5) Having explored the ontotogical consequences that result from a denial of the PNC, Aristotle moves to consider the epistemological effects. Just as it is the case that al1 king will be potential, lacking recognition of the PNC as its causal principle. so too it must transpire that ourjudgements will be similarly indetenninate if the PNC is not operaiive as a principle for thought: for without it there can be no distinction between our assertions and denials.

And so Cor those who give this account this too accords, that also it is not necessary either to assert or to deny. For if it is tnte that [a thing is] a man and a not-man, clearly also it will be neither a man nor a not-man. For the two [assertions] there will be two denials, and, if there is a sUigIe former proposition compounded out of both statements, there must also be one latter proposition opposed to it What Aristotle is examioing are the ramifications which logcaily follow for thought from saying that sornething both 'is and is not'. This. he points out, is in itself an assertion which is subject to contradiction if the opponents thesis is, as is claimed. universally applicable. Whatever way these statements are combined, whether taking the predicates singly (man, not-naan; not man, not not-man) or as a pair, (manand not-man: not man and not not-man) they are self refuting and the outcome will be the same. it is possible neither to assert nor deny.58 To say this, however. is to interpose something between assertion and denial which is neither the one oor the other. Those who do this must, knowingiy or unknowingiy, deny not ody the PNC but also the PEM. which precludes the possibility of there kingany intermediate between the contradictories, assertion and denial.

Of opposites contradictories admit of no middle term; for this is what contradiction is - an opposition, one or other side of which must attach to anything whatever, i.e. which has no intermediate. The PEM is, in fact, entailed by the PNC so, of course, if Heraclitean opponents refuse to admit that there is any such thing as assertion and denial it can hardly be an added consideration for them that they are thereby denying something which is consequent upon this,

The discussion in r4 began with a request that an opponeot say something signïficant and substance and essence have emerged as the focus of the investigation. What has been bmught to light is the necessity of recogniùng that things have an essential nature that defines them and through which they can be known in their own self-relation. Now it must be established how it is that king is made meaningful for thought If a statement is to be in any real sense sigificant, Aristotle maintains, it must express either an affirmation or a negation of king for it is in the connections that the intellect forms between subject and predicate that tnith and falsity are to be found. As substance reveals its essence to thought, its operational principle, the PNC is found to be reflected as a psychological law in the operation of the intellect as it affims and denies.

The point redched herc is exactiy ihat exmrne sapticism attributeâ by Timon to Ppho. who lîved at the same time as Anstale, king about 38 when Anstotle died in 333 B.C.. Cleariy Fymho rccognizes the prirnary Iaws of the understanding as ARstotle has bcen expounding them in Book r, rejecting each in ils turn. Thus. he asserts 'conçerning each thing that it no more is than is not mnciple of Finite Idcntityl, or than bthis and is not [PM,or than it neither is nor is not [PEMJ.=pi &Veç EKO~Eyovraç, ii.ri 06 pWvgmv, 4 O\~KËmv, 4 ai Ëm, ai o\in Émv, on' &K Ëmv. Aristcxlcs, in Euscbius, Praep- Ev. 14 18 3-5. Without assertion & dehl there is no finitude for thought (lûûSa7-b2) The options that present themmlves for thought must now be elucidated. Those who say things can be said simultaneously both to be 'so and not so' mut further clarify their position and assert either that:

assertions and negations are similarly compatible, or that the theory is true of some statements and not of others. If the latîer is the case. ihen the PNC is admitted at least a Iirnited operability and it cm no longer be asserted that everything is 'so and not so.' At this stage Aristotle allows. for the first tirne. a Iittle reasonable doubt as to the universal validity of their argument to be entertained by his opponents. Indeed, on the basis of his argument to date ( 1Wa2@33), Aristotle, as Alexander argues,s might anticipe that it rnust be admitted ihat it is absurd to persist in denying that substance can be judged to be apprehensi ble as its essence. However. if they remain obdurate and continue to insist that a thinp can be said in every case to both be 'so and not sol it must be examined what further absurdities can be seen to follow upon this.

Those who insist that. without exception. things cm be said to be 'so and not so' are claiming that the negation will always be true wherever the assertion is. But this pair of contradictory statements can itself cm be taken as a single conjoint proposition. such as 'A is oot-B and B', which enpenden corresponding conjoint counter propositions of whicb Aristotle now puts forward two:

either [uthe negation will be true wherever the assertion is, and the assertion true wherever the negation is, or 121 the negation will be hue where the assertion is, but the assertion not always tme where the negation is. Resumably one could also put forward a third counter proposition. namely that the negation will be tnie wherever the assertion is but the assertion true when the nepation is not always so. This would. however, be consonant with what has already been allowed as

59 '11 would seern reasonable for hem to say the latta, since he has shown conceming substance. the specific form, and the things predrcated esscntially, that it is evidently absurd to say something is no[ that in which its king çonsists, that in accord with which each being is what it is." miko ôk e.ijAi0ycq &~@IEV OV My~dutim' aOY. &i aR r& rm mû oimiiou ~i6oqrai n3v év ri Bon raniyopoupkvov Z&i& QHIVEpe GDKOV OV 6 CLfl etvm roiho A&E~v, t?v 6 ivc&@ TO eiva ai KU@ 8' Zanv Z~asrovt6v 6vrov 6 kmv. Alexander of AphrodiSas, Metuph., 294.4-8 (Hayduck d). a possibility ( 1008a IO), that in certain oises only one of a pair of contradictones may be said to be tme, and so would not add to the discussion. If it were to be the case, as in [21 above that the non-king of something couid be asserted to be knowable, then Anstotle argues. it must also be the case that there is possible a corresponding affirmative proposition; for the non-being that is knowable is always the non-king of sornethinp. Thus, 'not-man' is knowable only as what is other thao 'man' which must hence also be knowable as the subject of a true jud,oement.

When, as in [1] above, dl that is asserted is denied, the implications of the predicates may be investigated either by examininp them separately or as conjoint propositions. Taken as the latter ( lûO8a20-Tn they are, as Aristotle has already pointed out, cornpletely self- refutatory ( 1008a4). Nothing is thereby either asserted or denied so that our opponent say s nothing and nothing exists, not even our opponent himself as it would seem. But. as Aristotle remarks with meacerbity, *How could such nonexistent kingspeak and waik as he does" ( 100€?a23)?Whether the predicates are taken conjoint1y or singly ( 1008an-bl)it must be stated once again that the outcome remains the same: nothing wi11 be or be knowable for there will no distinction of any sort, no sameness that can be differentiated from what is other, so that al1 will be one on1y in its very indeterminacy .

If contrary predicates were truly to be singly applicable certain other consequences would inevitably result. A11 that is stated to be affirmed mut immediately be denied and vice versa ( 1ûû8aîû-30). If one were to Say "Socrates is musicaln, for example, this is to be irnmediatel y refuted by the contradictory statement "Socrates is not musical" so that the man making a true statement must immediately contradict it and admit hirnself to be in error. In effect he says nothing.

For he says neither 'yes' nor 'no', but 'so and not so';and again he denies both of these and says 'neither so nor not so', for othenvise there would be something definite. Those who would deny the PNC as the operative logic of the understanding have been understood to do so as a necessary consequence of their rejection of the PNC as a law of king (1008a24). If nothing is there in its own self-identity to what can statements of tnith and falsity be applied? If the naturd worid is no more than an everchanging flux in which noihing exists as substance or essence then there is nothing that is knowable, for nothing is and there is thus no stable finitude for thought AristotIe has dnven the argument inexorably to a position from which there is no escape. the extreme Heracli teanism of Cratyius:

who finaily did not suppose it to be necessary to say anything but ody moved his finger, and criticized Heraclitus for saying that it is impossible to step twice into the çame river; for he himself supposed not even once [was possiblel.

AU men make anquaiified jodgements (1008b2- 1009a5) The discussion as it has unfolded to this point leads to the conclusion that i t is necessary to embark upon an investigation into the siagnificaoce of human judgement. To this point there have been contraposed two fundamental positions each a kbyq arparq to which is linked, through affirmation and denial, the logic of tnith or falsity. To the contentions of the Heracliteans, w ho declare that everything is in flux and therefore must perfom assert that everything 'both is and is not', Aristotle has couotered witb arguments which reveai the necessity of accepting the PNC as a fundamental law of both king and knowing. Truth and faisity, it must be emphasized, do not lie in king which always is just what it is:

for falsity and truth are not in things - it is not as if the good were itself true and the bad false - but in thought. Hence, tmth and fdsity are to be observed in the statements that we make about being and these in their turn &se in the activity of the intellect as it connects and divides subject and predicates in assertion and denial.

For the true judgement afhwhere the subject and predicate really are combined, and denies where they are separated, while the false judgement has the opposite of this allocation. It is here, in the act of the intellect, that we must çeek the source of the problem for it is evident that there are some, like Aristotle, who judge that the PNC is the causal pnnciple of thought and othen who would deny this to be so. So it must now be açked:

again is he in emrwho judges either that the thing is so or it is not so, and is he right who judges both? Where, indeed, do judgements of the latter type lead except to utter incomprehensibility. Anyone who would judge things at the same tirne both untnie and tme can communicate nothing that is intelligible.

And if he makes no judgement but 'rhinks' and 'does not think', indifferently what difference will there be between him and a vegetable?

It is perfectly evident Anstotle concludes. that man by the very fact that he is man makes specific judgements. So whereas it is of course possible to deny outwardly tbat anythinp is or cm be said to be or not be any one thing, it is certainly not possible that anyone who seriously considers what is entaiied by such a proposition could continue to believe this to be achrally the case. Indeed this very thesis was placed before us for exploration at the commencement of this discussion and its claims Aristotle must now regard as fulIy substantiated. To the followen of Heraclitus one can can only reiterate what was said at the outset.

For it is impossible for anyone to judge the same thing to be and not be, as some think Heraditus says, for what a man says he doeç not necessarily believe. Aristotle has now disposed to his own satisfaction of the A&oç arpa~oçof the Heracliteans but what of the account of those who judge as he himself does that a thing cannot be both 'so and not sol? Even if they are not completely correct in their judgements and so can not in the strict sense be said to be right they will. Aristotle concludes. certainly be more right than those who judge everything to be both 'so and not sot, for being will be affirmed as having some sort of nature ( 1008b57).

What has been absent from the argument to date is any consideration of a conception of 'becoming'. In the pure dichotomy of the logic of the PNC a thing either lis or is not'. whether ontologically or psychologically mandate& It is obvious, however, that the fixity of this logic of 'being' and 'not-being', as it has thus far appeared, is insufficient to adequately account for a sensible world which undeniably can be observed to be in unceasing change. While a full examination of this problem mut await the rniddle books of the Me~aphysics.Arktotle, as a first step in addressinp this issue, reviews the adequacy of our knowing to the being of the sensible. In fact, from observations of how men actually act in relation to their environment, it is possible to conclude that: as seems likely all men make unqualified judgements, if not about al1 things still about what is better or worse. The position taken by Aristotle's opponents has been repeatedly revealed to be incapable of producing any intelligible exposition of thought and so the claim that a thing may be said to be 'so and not so' in any sense other than as the potential must once more be refuted. This does not mean, however, that the opposed position, which is to say that a thing can be judged to be 'so or not so', cm be unquestioningly adopteci. If this were indeed to be the case ail judgements mut be correct and since people differ in their conclusions as to the nahme of things this obviously is not the case. What our primary judgements produce are opinions and not knowledge. Recognizing that this is the case is to ipso fmro acknowledge the inadequacy of our judgements to the king of reality. This being so. Aristotle says:

they should be dl the more anxious about the truth, as a sick man shouid be more anxious about his heaIth than one who is healthy; for he who has opinions is, in cornparison with the man who knows, not in a healthy state as far as the tmth is concerned,

When we actually examine the judgements that people make it is to be observed that although they rnay be incorrect they are not al1 equally sa Between the toial scepticism espoused by the Heracliteans and tmth as the identity of knowing with kingthere lies a spectrum of opinions which rank as more or less wrong (or right) in the adequacy of their judpment of reality ,so that someone w ho supposes four things to be five is les wrong, and hence more right, than a pemn supposing these sarne four things to be one thousand (1008b35). From our uncertain judgements. plucked frorn the flux of the sensible, we pdually corne to discem those that are more true than others. By continually examining and refining these relative determinations we can, Aristotle indicates, rnove closer to that absolute truth which is the identity of our knowing with the king of reality. It rnight be thought premature at this stage in the argument to state categorically that there is such an unqualified truth, but nevertheles: even if there is not, still there is already something more Cinn and more true, and we should be rid of the unqualied account which prevents the determination of anything in our thought. An essential step in that movement from what is rnost knowable to us to what is most knowable in itself is to reveal the incornpleteness of the sensible world and its dependance upon a higher principie of being and intelligibility. This principle while greater than the sensible must at the same time be fuiiy comprehensive of it if the Platonic ~opmpkis to be circumvented. For there to be any true king or knowing, Aristotle has argued in r4. the unchanging must be seen to be present in the flux of the sensible providing an underiying stability to the naiural which renders it explanatory As Aristotle develops his metapbysics be must take up into his own position the thought of both idealist and materialist predecessors. In Book r Aristotle is not yet concemed to show how essence is to be understood in itself or with a critical examination of the Platonic position on essential natures. As he sees his task he must establish how, in the flux of the sensible, it is possible to forge that fiat tenuous link which will reveal the possibility of a ground for the changing in the unchanging. It is to the subjective idealism of the sophists that Aristotle will next tum in this quest, for it is here that he sees the sensible first to be taken up into the intelligible. as the focus of indeterminacy is moved from the sensible particular to the individual knowing subject. THE UNCHANGING FOUNDATION OF THE SENSIBLE

As Aristotle tums from the logicai defence of the pnnciples of the understanding to an examination of those considerations which have given rise to the view that the sensible is by nature contradictory. he knows that it is not sufficient simply to show that there is an underlying stability to the natural. If a 'first science' is to be tnily universal nothing must escape iis comprehension, and its fundamental laws, the principles of the understanding, must be fully extensive of al! reality. Hence it is that in the latter half of Book T, against the background of a seerningiy interminable flux. the Aristotelian doctrine of potentiality and actuality begins without ceremony to make the necessity for its presence felt. What will emerge from the analysis of the sensible is an understanding of the direction that the investigation must take if substance as the object of first philosophy is to embrace both the unchanging and the changing. The apparentiy contradictory nature of the sensible as it manifests itself to the perceiving subject is, for Aristotle, itself an illusion that must be dispelled as the unded ying parameters which both shape and define dlsensible chan,=e are revealed. Motion, Aristotfe is adament, is neither indeteminate nor self-contradictory. In the final analysis there is no flux, only substances with their accidental attributions ordered to them in a determinate and non-contradictory manner through the relation of the potential to the a~tual.~OThe npb~Ëv ontology of being as substance and essence explored in r' 1- 4, with its concomitant acceptance of the primacy of definition. must be retained. Frorn a non-specific logic of non-king as Ëwpov, however, Aristotle will move in ï 18to establish the foundation for the extension of the logic of non-contradiction to include a new fom of non-beinp, the determinate ontology of non-being xpk TL, through wwhh the potentiality of the sensible is comprehensively ordered io its pnnciple as complete actuality.

Those who reject sabstance & essence have a common position (1009a5-22) Having asserted in r4 that the consequence that must logically ensue from a rejection of substance and essence is the elimioation of king and knowing, Andotle now asks why it is that people have been led to the consideration that things can be 'so and not so'. In establishing the theoretical basis for his philosophy, Aristoile is keenly aware that he cannot just argue the logic of his own position. He must, in addition, anticipate and counter al1

Behier maices this point well. "Thenis no universal flu..: ihere is only a collection of movemmis, cach one lirnited in a prtxise way by an initial and a final state. Thcre is no flux of subsiantid forms; the substanbal form, which as final cause, has directed the series of modifications which have [ed to its king received by matter, rcmains permanent and identical, Knowlcdge, with its permanent concepts, pencûatcs changing things themselves-' Bréhier, 189. possible objections and alternative accounts which could conceivably allow doubt to be cast on his most fundamental of precepts, the essential nature of substance. These arguments cannot be arbitrarîly dismissed but mutbe carefully and completely delineated and then systematicall y addressed. Only by so doing cm the integrity of the fundamental logical assumptioas which underpin the Aristotelian philosophy be maintained inviolate. Sextus Ernpi ncus. in a very different cause. affirms the importance of proceeding in this manner.

For just as, in a siege, those who have undermined the foundation of a wall find that the towers turnble down along with it, so too in philosophical investigations those who have routed the primary assumptions on which the theories are based have potentially abolished the apprehension of every particular theory.

Anstotle begins in r5 by taking up a point he had earlier made on the logical consequences of asserthg that contraclictory statements can be true of any subject at one and the same time. It is clear, he had there noted, that if this is admitted then al1 things will be one, for evewngwill be as much one thing as anything else and so there will be no way of distinguishing between, for example, a tnreme, a wdl. and a man (1007b20-22). In defending and substantiating what must be detemined as immutable in his own account. Aristotle wilI seek, in tum, to uncover that which is fundamental to the counterclaims of his opponents and expose its limitations. In so doing, it is important that he first establish any underiying commonalty that characterizes the views of all those who would directly or by implication deny the essential nature of substance. At the same time, it is evident throughout r5 and r6 that Aristotle, while always maintaining his own philosophical perspective and his focus on substance, first draws al1 these opponents within the strucnire of the argument developed by Plato against Rotagoras in the Theuetetus. While ultimately be must part Company from Plato on the nature of reality it will be with the assurance that there is a necessary movement fonvard out of the sensible for thought. firmly punded in a common and unassailable foundation which leaves nothing extemal to it.

That the views of Rotagoras cmbe linked to the long succession of Re-Socratic philosophes who directly equate the intelligible with the irnmediacy and particularity of the sensible has ken noted by Plat062 and Aristotle in the opening words of l-5 echoes this same sentiment (1004a6). The position of Rotagoras, that everything is as it appears to the

61 ra09rep yap Èv mi5 YCO~LO~I&XLSoi dv&&k~ov mii ai~qhopemq mV- avy~~a@po&voq&own wiy May, O- oi & rai5 $tkx~%@i5oicrfy~or ni5 xpchaq rôv xpûy~~amv~O~~LÇ XEL~W@EVOL ~vQFLEL njv ILO[\KiY xpciypamç ~amikq~vfifk~icacnv. Sextus Empiricus, Adv. math, i., 3 62 Theaetetw, 159A perceiving subject, can be found to result, he says, fmm the same way of thinking that was earlier atîrïbuted to 'many writers about nahire' (IûCKdl-3). It is a matter of record that individuais differ in how the worid appears to them and consequently they bave confiicting beliefs Given that al1 such appearances and betiefs about an object are true, as Rotagoras argues, then clearly we must say that this object is 'so and not so' ( 1009alI).

For if al1 opinions and appearances are tme it is necessary for al1 things to be at the same time true and false. Whereas the wind is cold to me it is warm to you. so that for each of us our particular beliefs are individuaily and undeniabiy me. Since for the Protagoreans. as for the Heracliteans, everything can thus be shown to be 'so and not sol nothing for these thinkers can be said to be any one thing and this, Anstotte concludes, draws al1 these positions into a commonaity with Anaxagoras in making al1 things potential.

And this must be accepted by those sharing Protagoras' views... and it becomes the doctrine of Anaxagoras, that al1 things are rnixed together; so that nothing really exists. And so they seem to speak of the indefinite, and supposing themselves to speak about king they speak of non-king;for king is the indeterminate potentiaiIy and not actuatIy.

At the heart of both the rnaterialist and sophistic position lies the Heraclitean doctrine that 'al1 is in flux' which is based on observation of the endlessly changing sensible world. From this arises both the contention of the matenaiists that knowledge is aicrmoiç and that of the sophists that truth lies in appearances and each of these positions Aristotle will examine in its tum. The mateiialists, immersed in the natural, are without a logos of the sensible and for them knowing is held fidycaptive within the flux so that, in effect. the knowing subject has no reality distinct from the sense object. It is with the sophists that there will be found to emerge the beginniog of a thinking activity. an ordering of the sensible to the intelligible, in which the cause of something king a 'this' is seen to reside in the perceiving subject. in moving in the direction of subjective idealism, however. the sophists abandon the object of sense as devoid of any extemal reality. The apparently contradictory natore of the sensible (1009attb12) In the preceding chapten of Book T, Andotle has developed the concept of substance as a principle of finite identity delineated by a logic of non-contradiction. He has yet to show, however, how this principle can be operative when confronted with a world in motion. Those who, confronted by the seemingly intractable contradictions of the sensible, really feel the difficulties, Aristotie notes ( 1O09a22-23; 1OO9b 1), are forced as a result of their observations to deny the PNC and clah that things can be 'so and not sot. The earlier passing references to Protagoras and Anaxagoras and the long heritage they represent will now be expanded upon and, indeed, will assume a key rote in the argument as substance for the first time comes into direct confrontation with the flux. As Anstotle undertakes bis examination of what may be temed the Heraclitean tradition in r5. he starts frorn the most extemal and abstract relation between fomand content so that nothing will escape his net and hence faii outside of the purview of fint philosophy. His object will be to recover from this CratyIan flux the sensible object, substance as 'separate' and a 'this', and to establish that it is through essence, as the universal 'such' resident within sensible substance. that content is brought into an ordered relation with form and the changing world of appearances rendered intelligible to thought He will be guided in his deliberations by two major considerations which form the basis of his understanding of reality, the concept of limit auociated with every dimension of causality, without which there can be no intelligible reality, and the existence of a first principle and cause, an unchangiog ground for the sensible in the intelligible. The fint he has addreçsed in some detail in Book a, the second is the final objective of the Metuphysics which, although not to be fully achieved until Book A .is repeatedly invoked as Aristotle in developinp his argument draws attention to the inability of the sensible to fully account for its own being.

But evidently there is a first prinaple, and the causes of things are neither an infinite series nor infinitely various in kind.

Nearl y al l his predecessors, An stotle States ( 1OWMO), have made contraries the principles of the sensible. Thus we find the one and the many, love and strife, the full and the void and even Fannenides and the Ionian physicists cm be included, "for Parmenides treats hot and cold as principles under the names of fire and earth and those too [make contraries the principles] who use the rare and the deose."63 The importance to be attached to ihis must in no way be minimized for it is through the stabilized relation of contrariety that the

63 Physicu, 188Û19-20. endless othemess of the sensible flux is first subject to limit by thought and thus becomes inherently howable. It is this albeit implicit recognition of the si@icance of contrariety that provides Aristotle with the common beginninp point he seeks as he begins to take up the thought of his predecessors into his own in the search for the substantial nature which lies hidden within the endless nepativity of the flux. As Anstotle understands it, the problem with the thought of his Re-Socratic predecessors, from which a beginning will now be made, is that whereas they al1 rnake contraries their principles and they recognize that there is a logical retationship between these contraries they are not able to give any account of it.

When these natural philosophers observe the sensi bi e world, Aristotie says, they see contraries corning to be from the same thing. Since they are agreed that it is not possible for something to corne to be from that which is not (1009a25; 1062b2425), they conclude that the contraries mutnecessarily mutually coexist in everything and that therefore it follows that "coatradictories or contraries are tme at the same tirne" (I009a.24-25).Hence:

as Anaxagoras says ail is mixed in al, and Dernoaitus too; for he says the void and the hl[ exist aiike in every part, and yet one of these is being and the other non- being. Anaxagoras, it is on record, held the position which Aristotle attributes to him here. As he states: "No Thing cornes into king or passes away, but it is mixed together or separated from existing Things. Thus they would be correct if they cdled coming into king 'rnixing', and passing away 'separation-offOn6-' From Aristotle's perspective, however, Anaxagoras can give no account of how out of his mixture it is possible that anything can either be delineated or determined as any one thing. Dernocritus, Aristotle mi@ argue, in identifying elements whicb can be equated with being and non-being in the sense of 'same' and other', has recognized the necessity of a Iimiting principle as the basis of delineation of a multiplicity of separate physical things, a kind of non-being which is hpovand not simply 'nothing'. However, Dernocritus has no formai cause to differentiate his 'being' and so li ke Anaxagoras cmshow nothing to be any one thing. Leucippus and his adateDernocritus Say that the full and the empty are the elements, calling the one being and the other non-being; king is full and solid and non-being is empty. And since the void exists no less than body, non-king they Say exists no les than being. And these are the matenal causes of exkting t hings. What Aristotle w il1 proceed to argue is that at the root of the problem for ail these thinkers is an inability to provide a satisfactory explmation of change. This is manifesteci in their failure to respond adequately to Pannenides' chailenge to say how non-king can be; a criticism from which not even Plato will be exempted by Aristotle. Cornpounding the problem in the oatural philosophers is their failure to recognize the derivative and incornplete actuality of the sensible, so that they find themselves unabie to give any account at dlof its mobility. By contrast, implicit to ail of Aristotle's thought is a recognition tbat the sensible at every level has a rt5h "God and nature make nothing without a purp~se."~~This is first evident at the elemental level in the detemiinate contrariety the sensible world exhibits as "everything that comes to be or passes away cornes from. or passes into, its contrary or an intermediate state. n66

That the observations of these thinkers do not lead them totally astray, Anstotle is prepared to alIow, for there is a sense in which sensible things can be said to be 'so and not so'. although noi in the same respect Whereas it may seem to these observers that contraries coexist in the sensible ihis is through their failure to distinguish between what is potentially and what is actually the case, Aristotle points out.

For the same thing cmbe potentially at the same time two contraries, but it cannot actually, While not at this stage of the argument in a position to unfold in any detail his own developed theory of potentidity and actuality as an account of change, Aristotle will seek in Book r to establish its theoretical foundaûon through an exposition of the fundamental nature of change ( 10 1Oa 1 1-33 and an extensive exploration of the limits of Protaporean relativity ( 1010bl-t 01 1b 12) which allows him to establish essence as a detemiinate nature underl ying the flux of sensible appearances. By the end of r6 Aristotle cmreturn to this initial dilemma and confidently assert that the sensible is not inherently contradictory.

65 Aristotîe, DeCudu, 27la33. 66 Physica. 188b22-3. What must be understd, Aristotle will maintain in I7, is that contraries which appear to be mutuaily coexistent are. in fact, in a miprocd and determinare relationship of king and non-king through which the essentiai nature of each contrary and its determinate privation is actually or potentially present as an affection of the sensible object ( LOI 1b EZ).The driving force of the whole argument, as he continues to make evideot, is the fundamental tenet that the sensible world as an incomplete actuality must be grounded ultimately in a substance which is itself unmoved and not subject in any way to change.

And again we shall ask them to believe that among existing things there is afso another kind of substance to which neither movement nor destruction nor generation at al1 belongs.

The confusion which bas arisen from the observation that the sensible is of its very nature contradictory, Aristotle now points out, is further exacerbated by a pned recognition of the unreliability of the seoses. I t is clear from experience of the sensible world that sense impressions vary not only between species but within the sarne species and even within the same individual over time. This leads the sophists to infer that such 'tmtht as is to be found in nature is only that which is apparent to the individual sensing subject in the irnmediacy of sensation.

And so which kinds of things are true or false is not clear. For this is no more true than that, but both are alike. The inevitable conclusion that results is that it is not possible to make judgements based on experience (1009b 1- 13). As far as the sophists are concemed there is no finitude to be found for thought in the sensible, no rationale which will allow underlying comrnon natures to be discemed. There are only an untold number of interacting variable parameten impinging momentarily upon a perceiving subject and therefore it must be said that no amount of accumulated experience cmcarry with it any predictive weight.

And this is why Dernoaitus, at any rate, says that either there is no [objective] tmth or to us at least it is not evident. The inclusion by Aristotle of the materialkt Dernocritus in this elabration of the sophistic position, which carries with it a rtjection of any sensible reali ty ,rnight seem at first sight paradoxical. How ever, w hile Dernocri tus postdates au unded y ing ground for the sensible in the atoms. he considers them to be for al1 practical purpose unknowable as 'things in themseives'. As a result, aithough his position is materialistic, in practice his understanding of sensation has similarities with that of Rotagoras. as Anstotle recognizes.

The identification of knowledge with sensation (lOO9b1238) The fundamental problem which gives rise to the conclusion that the sensible is contradictory is to be found for ail these thinkers, Aristde asserts, in the fact they they beiieve knowing to be a physical process. a kind of synchronous resonance between the individual knower and the sensible milieu in which he fin& himself irnmersed. Since they dl subscribe to the view that 'like is perceived and known by like' the difficulty arises for them in understanding how error is possi ble.6'

In general it is because they believe knowledge is sensation and this to be an alteration that they say what appears in sensation must be true; for it is for these reasons that both Empeclocles and Dernocritus and, one may say, a11 the others have fallen victim to opinions of this sort, ln support of this contention, Aristotle proffers a number of examples designed to illustrate its wide applicability to the thought of his predecessors. The extant fragments of Re- Socratic writings certainly lend credence to his assertion that thought was considered a phy sical process. Empedocles. i t is evident. maintaioed that the physical eMuences w hich are given off by al1 bodies, animate and inanimate alikeP8 enter the body through channels particular to the various senses69 and collect about the heart: nourished in the seas of blood which courses in two opposite directions: this is the pIace where is found for the rnoçt part what men cal1 Thought; for the bld around the heart is Thought in mankh~d.~~ From this Empedocles concludes, as Aristotle reports. that the knowledge men have changes according to their physicai condition ( 1009b 17-20).

Further evidence illustrative of the fact that men suppose knowledge to be equated with physical alteration is to be found. Aristotle notes, in a quotation of Parmenides taken from the "Way of Opinion."7 1 Here Parmenides, reporting j ust those prevailing opinions which

67 Dc Anima, 426b26-42'7a6. 68 DK3 t B89 69 DK31 A86 DK3 1 B 105, trans. Freeman, 63. The same passage is also to be fwod in Theopbrastus, De Sensu* 3. must be guarded against if the "Way of Truthwis to be followed states that it is in accordance with the composition of "their mucb bent limbswthat men think ( 1009b24). Theophrastus provides us w ith an elaboration of Parmenides' argument: For according as the hot or the coid ptedominaies, the understanding varies, that king bettet and purer which derives €rom the hot..But that he also attributes sensation to the opsiteelement in its own right is dear from his saying that a dead man wili not perceive Light and heat and sound because of the 1- of fire, but that he wiil perceive cold and silence and the other opposites. And in general, al1 being has some share of thot~~ht.~z Anstotie takes up much this point in bis reference to Hector who while lying unconscious is 'thinking other thoughts'.

Evidently then if both are fonns of knowledge, the mal things alço are at the same time both 'so and not so'. Resurnabl y w hat Aristotle means is that if the same exted sense object can provide Hector with entirely different sets of thoughts, which is to say knowledge, depending upon his state of consciousness, the sense object must itself be 'so and not soi.

The establishment of a direct physical connection between sense object and sensing subject and its unmediated identification with knowledge allows Aristotle to expand his argument from its ground in the flux of being to what it entails, a consequent and necessary acceptance of the relativity of howing. At the same time his net is widened to encornpas al1 of these opponeots, whether PreSocratic natural philosopher, or sophist. By this means he bas further bound by necessary connection al1 aspects of the opposing Heraclitean tradition and the counter arguments he will now mount against it will be augmentative in undemiining its foundations, while sirnultaneously affording him the broadest possible base for the establishment of substance in the sensible.

Despite the force of Aristotle's conclusions, it would be incorrect to assume that the Pre- Socratic philosophers were themselves aware of the logical consequences that must follow from their identification of knowledge with sensation. At best the senses seem to have been regarded by them as unreliable indicaton of the tme state of things. Thus Anaxagoras says that "owing to their infiirmity we are unable to judge what is tr~e"~~and even Empedocles was in no doubt as to the fact that truth does not reside in the sen se^.^^

72 Theophrastus, De Sennr. 34(Dm A46) tramlaicd by John M. Robinsm. An ln~roducrionfo hriv Greek Philosop&, (Boston: Houghton Mifflin, 1968) p- 124- 73 W.math vii. 90 (DK59B21). 74 MV- math. vii. 133. Dernoaitus firmi y and repeatedl y rejects the position that the senses provide us w ith knowledge of what is d.as Sextus Empiricus75 reports in some deiail, summariMg Dernocritus' position thus:

Sensible objects are conventionally asssurned and opined to exist, but they do not truly ex&, but only the atoms and the void [exist1. In his "Wayof Tnith" Parmenides dso speaks of the futility of this way of thinking for human knowing. But next 1 bar you hmthat way along which wander mortals knowing nothing, two-headed [in two mincis1 ,for perplexity in their bosoms steers their intelligence astray, and they are camed along as deaf as they are blind, amazed, uncritical hordes, by whom To Be and Not To Be are regardeci as the sarne and not the same, and (for whm) in everything there is a way of opposing stress7 The thoughts Parmenides expresses, clearly pinpointing the problem the Heraclitean flux presents for knowledge, are taken up by Anstotle in the argument in r5 as he pursues his own response to the challenge Parmenides lays down to explain how king cmbe thought and spoken. To be c-ed along passive1y, like a leaf in the wind. blown hither and thïther in thought by each passing sensation, is not the life for a man. One might as well, as Piato rernarked.78 be a pig or a baboon or any other sentient creature ai dl. Al1 these natural philosophers recognized this to be the case in practice but weighed down by their equation of Emh~,~1with oioûqmq as aMoimç, physical alteration, none could release thought from the flux in a way that would enable them to even formulate an inquiry into whether there could be any objective rational basis by which the sensible could be rendered intelligible. As Socrates cornplains in the Plmedo. he was at first delighted on leaming that Anaxagoras had said that Mind was the director and cause of everything only to have his hopes subsequently dashed by the discovery that, in fact. Anaxagoras could show no cause why mind should adon the sensible.79 It is Dernocritus perhaps arnong these thinken who is most keenly aware of the nature of the airopia with which they are confrooted In a dialogue between the senses and the intellect he has the senses respond to the intellect thus: Miserable Mind, you get your evidence hmus, and (then] do you try to overthrow us? The overthrow [of us] will be your downfa~l.~~

Mv. mafk vii. 135 140. Adv. m~h.vii. 135. DK38 B6, tram. Freeman. 43. lkaetetus, WC-9ûC. Ph&. 161C. DK68 B 125, crans. Freeman, t 04. Aristotle, in reflecting on the philosophical achievements of his predecesson the naturd philosophem is not inclined to dismiss them surnmarily in the manner of Parmenides as 'uncritical hordes'. As always he recopises that it is tmth itself which is the underlying driving force of their search but the dificulty of the hpiathat presents is not to be underestimated.

For if thse who have seen the most of such îruth as is possible for us (and these are those who seek and love it most)-if these have such opinions and express these views about the truth, is it not natural that beginners in philosophy shouId !ose heart? For to seek the mith would be to follow flying game. As the problem has fomed itself for the naturat phiiosophers through their understanding of sense knowledge, it has becorne clear to Aristotle that they have reached an impasse. Being, knowing, and change, the explanatory parameten of the sensible, are not only confounded but conflated inexorably within the unceasing flux. Whether one says, as do the Heracliteans, that everything is 'so and not so' or, as does Anaxagoras, that thjngs are 'neither so nor not so' there is no finite identity only the endtessness of a universal abstraction. It is from this position of sheer and uttet negativity that Aristotle will now begin his own attempt to draw the sensible within the bounds of intelligibility. The exposition of the fundamental nature of change (1010al-37) Without an understanding of the true nature of change there cao be no progress in overcoming the difficuities which the Re-Socratic ampia presents. What binds the thought of these thinkea is lhat they identify the sensible world of their acquaintance with the king of al1 reaiity and as a result, based on their observation of sensible change, they affirrn that nothing can be truly known.

And again because they saw that ail this world of nature is in movement, and about that which changes no true statement can be made, they said that of course, regarding that which everywhere in every respect is changing, nothing could be tntly affirmed. To hold fxedly to this position leads inevitably, as Plato had earlier n~ted,~to that extreme fomof HeracIiteanism, attributed here by Aristotle to Cratylus ( 1010a 12- 15). and consequently to the complete rejection of the possibility of any meaaingful discourse or action,

Two major considerations emerge for Anstde in the constmctioo of bis response to those who assert that the sensible is inherently contradictory. In the first place. he observes. these thinkea consider only the indeterminacy they observe in the natural world of their acquaintance and they must be show to be rnisdirected in assuming that they can extrapolate from this to the whole of reality (1010al4). Secondly. seeing everything in nature is in motion they conclude that there can be no knowledge of that which is in change (1010a7- 14). In response to this latter contention Aristotle will hold thai stability is to be discemed within the flux and that the changing is grounded in an unchanging nature. which is to be equated with substance ( 10 lOa26). Once these points have been established it must also be reafirmed in response to those who hold such beliefs that. since the principle of the naturd is motion and ~hange,~2the sensible world as ultimately an incomplete actuality must itself be grounded in a substance which is fuily actual and necessarily unchanging ( 1010a34). If Aristotle is to successfully cross the Piatonic divide and achieve his objective of bringing the sensible into relation with the intelligible as its first principle 2nd cause he knows that he must show how this unchanging pnnciple is manifested in the changing. If he cannot do this then the natural world must be forfeit to the sophists or, at best. remain as he sees Plato has left it, a shadowy realm in which the fleeting instantiations of the aicsûqra serve oniy to recdl hazil y to mind that etedand separate reality w hic h. w hile ultirnately the being of what the sensible is not. cannot be causally comected to it.

As the argument bas been developed so far, earlier thinkers have been held to observe both that coniraries and contradictones corne to be out of the same thing ( 1009aZ3-24) and that everything in the naturai world is in a perpetual state of flux ( 101ûa7-9). Since none are able to give an account of change as becomings3 they can only conclude that i t is not possible to distinguish anything in its own self-relation. Hence. for Anaxagooras and Dernocritus al1 distinctions are found to be lost within one another, whiIe for the Heracliteans. contraries cmneither combine nor distinpuish themselves from one another. That there is some justification for the fact that these misconceptions amse Aristotle is prepared to admit, the source of the ampia king the complete dichotomy of king and non-being entailed by the Io& of Parmenides. To those that follow the account of

Physico, 1-13-14. 83 Aristotk, De Cm Con .317b29-30. says that the very idat 'that ming-bbe proceeds out of wihi ng pre-existing [was] a tbcsis which more than any other, preoccupied and alarmeci the cariiest philmophcrs" H.H. Joachim translater. Anaxagoras everything has being but nothing is any one thing whereas for the Heraeliteans, by contras&there is oniy process, endless non-king. What they have not kenable to disam, Aristotle States, is that king' has two meanings, that which is potentially the thing and that which is achially the thing:

so that in some sense a thing can corne to be out of that which is not, while in some sense it canot, and the same thing can at the same time be in being and not in king - but not in the same reqw&

In answer to Pannenides, Aristotle is prepared to grant that there is a sense in which what is, since it is, camot come to be and a sense also in which it cm be said that notùing cm come to be from w hat is net. indeed, he will incorporate these same tenets into his own theury of change. I-iowever, what he cannot allow is the necessity of the unqualified nature of these conclusions. What those enslaved to the logic of Parmenides have failed to comprehend is that, like being, non-king is not a univocal terni and there is a difference between absolute (ad.cûç) non-king and accidentai (raza (N~@&IC&)non-being. "We ourselves say that nothing cornes to be absolutely from non-king. Nevertheles [we say] such a thing can come to be incidentally f'non-bei~g."~S A detailed explmation of motion and change and the principles of the sensible which undedy it belong to the Physics. whose proper subject matter it is, as Aristotle has pointed out elsewhere.86 Notwhithstanding this, his response ( 10 lOalS7) to his Heraciitean opponents outlining hi s own understanding of the nature of change appears particdari y abbreviated. If the full force of his position is to be appreciated some elaboration is needed so that the points that he rnakes can be placed within their appropriate context Indeed encompassed within this short account, however perfunctorily expressed, is the whole movement of thought in the Physics. seen now from withio the perspective of Anstotle's metaphysical doctrine of substance as it ranges from the potentiality of the sensible to its full actuality in the first principle. Thus, from the complete negativity and abstract universality of the Heraclitean flux (10- 15) the argument moves thmugh the developing concept of substance (1525) to the establishment of an unchanging pundfor the sensible fim recognized in the etemity of the heavens (25-32)but ultimately in that completely unchanginp nature that is the fimt principle and cause of al1 that is (32-33).

84 Physica, 19la3a3 1. 85 Physica, l9 1b 15. 86 De Gcn. Con. 31 7bi4-15: Meysa 1062b3 1-33. Sensible change, as Aristotle has already detemiined, is a process in which time is an essentiai component 87 It is not that instantaneous traosmutation from non-king to king supposed by the theory of sensation which Piato attributed to the foliowers of Rotagoras,g8 in accord with which nothing can exist except in so far as it is king actually perceived. If such were to be the case then people would be blind and deaf many times a day Anstotle tartly remarks (1047a9). In response to al1 those who in accord with the Heraclitean tradition can see no stability in the sensible, Aristotie introduces his own theory of motion involving potentiality in act, the ordered relation of the changing to the unchanging. His first point is to establish that there is indeed something which persists through change for, as he states:

TO 'CE yàp ~o~UovE;CELTL TOG ~o~- kq~&vou, ai -coû yiyvopkvou jtiq civbyml TL &val ( IOIO~1% 19). that which is Iosing a quaIity has something of that which is lost, and of t!!at which is coming to be, something must already be. nius, the sensible when changing from one existent state to another remains in some rnanner in beinp. Indeed, motion cmbe defined, Anstotle states, as the actuality of the potential as such, fi roc 6uvap~iiiwq émZ~e~a.6 roioiicov dvqai~émv. and the buildable as buildable is ody red when it is king built, for when it is built it is no longer b~ildabIe.~9

It is not sufficient simply to show that the changing as changing is existent. it must aiso be shown that the sensible flux is able to reveal out of itself an unchanging nature that will provide a finitude for thought and hence the psibility of meaningful discourse. Whereas al1 a,pe îhat the contraries are the basis of intelligibility in the sensible, the problem Anaxagoras and othen among Aristotle's predecessors have encouotered has ken an inability to rezoncile the fact that contraries cannot combine with the observed occurrence of change from one contrary to another. In fact, Aristotle asseits, they are correct in thinking that contraries do not combinego but what they have failed to understand is that there is something that underlies these contraries, a imo~~ipwov,which is not a contrary but as itself the subject of change, holds the contraries within a unity that is prior to their essential

87 Physica. 33435. 88 Theaetetus, 156A- IslB. 89 Pftysicca 20lalL-19and paralklcd inMelqhysic~.1065b16-19 Gv m6 6uvcipet j roioVr6v emv Èvépyeiov Eyo civqarv On 8 Ùkqûij qopv. Neév6E i5ijhv- OmV yàp d oirOSopqu5v. 6 miohv a6d Akyopm ~iva~,E.wpyeia g, oi~oôo~ï~at. ai Ëm miko oi~oMpqcnç' Thm is a sense, Aristde says, in which the contraries are principlfs and a sense in which thq are not since contraries canot combine, Physica, 190b29-35. At Metaphysica, LW&-3. Aristotlc statcs that contraies are mutuail y destructive. opp~sition.~It is the contraries, form and its dprlmç, and matter as their underlying substratum,92 the koic~ipvov?that acting in consort as the priaciples of the sensible allow the process of change to be rendered intelligible.

That the persistence of the chaaging during the process of change must be punded ultimately in the unchanging is constitutive to the second point Aristotle brinp to bear on the exposition of the nature of change in r5. Thus, he argues tbat:

in general if a thing is perishing, there wilI be present something that exists; and if a thing is coming to be, there rnust be çomething hom which it cornes to be and something by which it is generated, and this process cannot proceed indefi nitely. What must be understood to be encapturd within this brief statement is Aristotle's contention that change, while it exists, is always constrained by its operational parameten. the principles of the sensible. Change when subject to analysis. Aristotie says in the Ph-ysics, is found to involve, a mover. a subject which is moved. and a goal towards which it is rnovedP3 There can, however, be no infinite regress and hence change, despite the fact that it is a proces occumng in space and time. is bounded ultirnately in every dimension by causal limits which codne it, secunng it firmly to its ground in the unchanging.

The evolving argument now centres on substance as that which underlies and persists through change. As material cause it exhibits a determinate poteatial to a range of accidental attributes, in the form of con- pairs in the categoria of quaiity and quantity. and as such it is the locus of change. However, Aristotle says:

Physica. 1190b33-35 and ahMefophysica. L 087a3 1-36. 92 Mamas SU~LSnph TL is the substrahun of change but underl ying this again, as what pcrsists through dl change, is &a as substantiai fonn, 93 Physka î25t16-7. With respect to the argument here in r5. Aristotle's understanding of change as he claborates it in the Physics may be briefiy summarized Whereas thcre may be a series of musai agents invoived in effecting ri change, as when a log is spii t by the axe w hich is moved by the arm which is moved by the man, there must always be an ultimatc causai agent of change (movcr) which is unmoved by anything other than itself (9ISQ4-3vih3)- What undcriies the contraries as a subjcct of change is one in number and a ~66~TL (190b7A9%), a particular individual thing such as a piece of wood or a man, that pcrsists as 'separate' and a Ws' tbroughout the change process. 1t is no€ t&e unmusical which changes to the musical but the unmusical man who becornes the musical man. It must also be recognized, Aristotic argues, thal "every goal of motion. whether it is a fm,an affection, or a place* is immovabie (E4bl l- 12). let us insist on this, it is not the same thing to change in quantity and in quality. Grant that in quantity a thing is not constant; still it is in respect of its form that we know each thing- Quality, as he hem infers has also a more fundameutal meaning as the differentia of the essence, that which penists through al1 accidental change as the substaatial form and focus of definition. With his usual economy of effort Aristotle has moved without comment fmm the contrast between accidental change in which qualities but not quantities are unemngiy sensed, to the knowledge that accompanies the intuiting of the essence of sensible substance. The sensible form, whether accidental or substantial, is never itself in motion and this must be understood as the basis for knowledge of the sensible. Protagoras. as he fitfully captures the accidental fomand subjezts them to the direction of vokhas identified the being of the sensible with the self-conscious rationality of huma subjectivity. However, battered unremittingly by the opposed forces of a contrarïety never fully within grasp, the unstable hok~ipvovof Protagoras cannot sustain itself in the order of the intelligible. It is only through the unchanging essentid nature of sensible substance as a 'this-such', a nature that Rotagoras steadfastly denies. that the being of the sensible can be brought into a stable relationship with vo* revealing out of itself its dependence upon the intelligible as its ordering principle.

What bas held thought in its bb~afor al1 these thinkea is their fixed fascination with the changing sensible world of their immediate experience and the primacy they accord it. If they would but abstract themselves for a short time from their dependence on what is accidental and contingent and reflect upon the cosmos as a whole they would see that, in fact. the changing world of our immediate experience is but a small fraction of visible

For only that region of the sensible worid around us is always in procw of destruction and generation; but this is, so to say, virtually no part of the whole, so that it would be more just to aquit this part because of the other part, than to condemn the other because of this, Surely, Aristotle argues with respect to this same point in Book K, we must accord precedence to the etemal rather than the changing cornponent of the cosmos and the more so in the matter of reality and tnith. When pursuing truth one must start from the things that are always the rame and suffer no change. These are the heavenly bodies; they are not found now in one condition and now in another, but are manifestly always the same and share in no change.

In the sublunary region the ceaseless cycle of individuals through the enduring but enmattered species is but a reflection of that desire for the etedactuality that it mimics. Beyond, in the spheres of the heavens plain for ail to see lies 'what is visible of the divine' ( 1- 18), the etemal and incomptible celestial spheres. Uncbanging, save only for locomotion, they endlessly return upon themselves as they traverse their cyclical paths in approximation of their ultirnate divine perfection. Beyond them rotates the outer sphere of the heavens, that single perfect unchanging primary movement which fuels al1 sensible change.

Therefore the first heaven must be eternal. There is thetefore also something whïch moves it. And since that which is moved and moves is intermediate, there is something which moves without king moved, king eternal, substance, and actuality. Beyond the heavens lies the first principle and cause of dl. "another kind of substance to which neither rnovement nor destruction nor generation belongsn ( 1009a37-38). Aristotle's metaphysicai enquiry, originating from witbin the sheer negativity and potentiality of a world in which no distinctions are possible and opposing to it the actuality of substance as fonnd cause, will gradually open up to thought the path which will lead to that full and perfect actuality which is its birthright. At this point he emphasizes once again th&, in facing those opponents who are held captive by the their chains to the sensible, it must at al1 times be kept in mind that:

we must show them and persuade them that there is something whose nature is changeless.

Indeed in a way Anstotle says, w hile pmviding one last reflection hem on the Heraclitean position on the king of the sensible, even those who clairn that things are 'so and not so' because they see everything in flux could be said to making al1 things unchanging; for since everyrhing already is there is nothing into which it can change (101ûa3137). The pure becoming of Cratylus is no more subject to change than the pure king of Parmenides so that the flux. while it can be expenenced, canot on this understanding ever be articulateci. It is the recognition of the nature of the kopiawhich has thus presented itself that is the irnpehis that will spur thought forward. What makes change possible. Aristotle w il1 argue, is the determinate relation of non-king to king whereby something can be said at the same time both to be, potentially, and not to be, actually, wbat it essentially is.

Imagination is not sensation (1010bl-3) Through a consideration of his own understanding of the fundamental nature of change Anstotle bas posited an unchanging foundation to the sensible ( 10 10a 1 1-37). However. if there is to be any knowledge of the sensible it must also be shown in what manner this stability cm be captured and taken up by thought. Those who have reduced thought to sensation, equating khpqwith aiathlarq, are noted to ioclude in their oumber not onl y the natural philosophers but also the sophists. The thought of the physicists must now be accepted to have ben exbausted. Lacking a unifying principle to underlie and stabilize sensible change, knowledge of the sensible, has remained for these natural philosophers caught inexorably within an endless negation and ciifference. Aristotle's attention as a result is now focussed specifically on the challenge presented by the sophists. These thinkers, while they remain committed to the position that the sensible is endlessly in flux. have nevertheless discemed a locus of stability in individual human subjectivity, a IjTLO~eipmovwhich defines man as the measure.

Protagoras holds that man is the measure of al1 things, of what is that it is and of what is not that it is not For Protagoras, the sensible world has its existence only in the immediacy of the sensory perception. The only kind of king for the sophist is the king of an appearance for the knowing subject; hence their assertion that 'al1 appearances are true'. The individual subject in taking up and ordering the content of the world to himself through sensation becomes as a consequence the very cause of its king. The very assertion by Rotagoras that the source of the king of the sensible is to be looked for oot within the sensible itself but in human reason, provides the irnpetus for thought to free itself from the flux and leave behind the Qnopia of the physicists. Wre that of Aristotle himself, the thought of

94 Sextus Empiricus, Pym. Hyp. ii. 2 16. Protagoras can be seen to encompass being at its most universal. It is thîs recognition by Protagoras that the human mind has the capacity to draw the whole of sensible reality within the unity of consciousness that Aristotle sees must be retained aud taken up into his own position. Yet, at the sarne time as he ncognizes the importance of the step that Protagoras has taken, it is imperative for Anstotle to refute the contention of the sophist that the measure of reality is to be found in the particularïty and variability of individual subjextivity .

It is to be noted that to this stage of the argument in Book r Aristotle has been describing appearances as 4aivop~va,under which pneral term he has jointly included the common perspectives of both the natural pphilosophers and the sophists ( 1009b l ;1009b 14). However, in taking up the sensible appearances as @C~C(IVO~EMand subjecting them to the active determination of consciousness. it is clear to Aristotle that Protagoras has created a oew form of being. the king of imagination, @awaoiaP5characterized by its irnmediacy, its SpeCiFicity and its transience, features which can readily be seen to stem from a theory of knowledge which assumes a direct equation of appearance with sensation. As a result. Protagoras, while identifying man as the measunng subject and thus in some sense a stabilizing centre in relation to the endless negativity of the natural. can yet daim that nothinp cm be said to exist in its own self-identity. pkv ~aaakb pqMv &van? That inevitably there is irnplicit within this position an element of self-contradiction will emerge in the final dismantling of Protagoras' thesis in ï6.

The formidable challenge that Protagoras presents to the conception that there can be any objective tmth or being at al1 is not lost upon either Plato or Anstotle and this is reflected in the attention they give to the refutation of bis position. What is recog~zedand accepted by both is that the dictum of Protagoras, that what becornes in the immediacy of sense appearance is tnie for the perceiving subject, is infallible in the ternis in which he defines it. In order to destabilize and negate the argument of Protagoras the true nature of his undedying prernises must be exposed (1010b3-101 1a2) together with the logical consequences which must necessary follow from them ( 10 1 la2- 10 1 1b12). To this end, two key precepts on knowing and being which have ken found to emerge from the thought of Rotagoras will be subject to examination. firstly. the contention that dl

95 A. Madi p.Alexonder of Aphr0disÜz.s: On AfitotIe's Metaphysics 4. (1thaca: Corne11 University Ress. 1993) n.722, commenting on lOIOb3 and noting the change from phainomena to phantasia at this point, sees this as posing a problem sincc "the opponcnts' thesis was not about phantasia understood in rr precise Anstotclian sense but about phantasia, or phainomena, understocxi in a much more gencral way." Undmtood within the context of Anstotle's developing argument this difficuity disappears. 96 mm,tus. 157A. appearances are equally, infaili bl y tme, and, secondl y. the consequent assertion that nothing exists apart hmthe perception of a knowinp subje~t?~

As Plato summarizes the position of Protagoras, ma&a 6pa icai aiaûqaiq scnk6v and since everything is as it appears to the perceiving subject it can be further concluded that aïdqqdpa roc 6vrq &i écmv rai &yeu6Èç dq kfipq oka.What is oecessary is tbat each of these fomof cognition, aidqaç, maoia.and &rnhpqbe differentiated and related to its proper object and it is with this in mind that Afistotk opens this section of r5 with an uncompromising assertion of his own position.

Regarding the tmth [wesay] that not every appearance is true; ht,even if (a) sensation of the proper object [of a sensel is not false, still (b) imagination is nof the same as sensation. What is critical for Aristotle to atablish, if thought is to progress beyond the subjective idealism of Rotagoras, is that a distinction is to be made between the act of sensation and the self-conscious awareness of the sensory experience. Discussion of these two points in relation to the sophistic position provides the rernainder of the argument in r5 and can be seen to be rooted in the argument of the De Anima. In his understanding of the nature of @cwraiaand its differention fiom ai&qolç it is to be remarked that Aristotle distinguishes his own thought from Plato as well as Rotagoras. Whereas for Rotagoras 'dl appcarances are true' and $av~aoiais km-q, for Plato 4awaoia is cornpletely arbitrary, exhibiting a freedom which places it at the lowest level of the Cave, with the consequence that 'dl appearance is false.' There can be no knowledge of the sensible, as far as Plato is concemed, except in so far as it is able to participate in the separate and unchanging worla of the intelligible Forms.

Aristotle, by conhast with both Protagoras and Plato, will seek to establish that neither of these extremes is the tme state of affairs; that it is correct neither to assert that 'dl appearances are true' nor that 'al1 appearances are false.' It is in the extemal objects of sensory perception that the intelligible forms reside, in Aristotle's conception, and hence it is only when $av~aaiahas taken up into itself the content of the sensory world that there is the possibility for know ledge. Nevertheless. the reception of the content of aïohor5 by

97 Theuetetusp 152CD. 98 Theue,rKS* 152C. 99 There have been a number of emcndatinis to the received text of this passage but the snw: of Anstotle's argument remains the same throughout and is consistent with his position in De rlnima, 418a12,427b12,430b29. t#uvraoia is indeed quite liable to emr, Aristotle will argue. for as has been already pointed out, it is not the same thing to change in quantity and in quality (1010aZ3-ZA). It is in the distinction that must be made between the sensation of qualities which are the proper objects of each sense, i8ta aidqr& and the integration of these i6ia with the quantitative aspects of reality in the common sense experience, ~oivi\aiaûqmg. 'O0 that Anstotle will identify Oavrada as inevitably a source of both tmth and falsity in its representatïon of sensible reality.

Essential to the success of the refutation of Rotagoras' clairn that 'dl appearances are tme' and the concomitant sepation of aidqaiçfrom the self-conscious activity of Oavraoia. is the requirement to establish that there is something which is extemal to the immediacy of aidl~ol5that cmbe known. Thus, in response to the attack of Roiagoras on objective knowledge. Aristotle, iike Plat0101 More him, will expose the incongruities that emerge hmdenying the fact that judgements are made independentiy of the immediacy of the seose appearance ( 10 iOb4- 14). To the rejection by Rotagoras of the possibility of any independent sensible redity Aristotle will counter with arguments from the perspective of his own considerations on the nature of change ( 1010b1430), concluding l3 with a reference to the absurdities which arise from Rotagoras' daim that the sensible does not exist apart from a sensing subject (101030-101 la2). It is at this stage, in his response to Rotagoras' attack on being. that Anstoile will part Company from Plato having argued the existence of an essential nature within the oaturaI which underlies al1 sensible change.

Objects of knowing exist apart from the perceivhg subject (1010b4-14) Those who conclude that dlappearances are equally mie derive this opinion from their observations of the sensible wodd, it has been pointed out (1009bl- 12). As an indication of this it bas been pointed out that the same O bject may appear di fferent to otber ani mals than to man and that betw een individuais and eveo in the same individual over time this cm dso be seen to be the case (1009bû-12). There is indeed evidence that such opinions were expressed by Aristotle's predecessorsl02 and, in fact, Aristotle is repeating here in summary what nato recounts in the TheMtetus:

IO0 See Dc Aninut, 4lûa7- 1 L where it is argued lhat the sense objezt îs spoken of as sensed rdaVrn in two ways, both as the spccial object ofeach sense and as that whicb is cornmon to al1 senses, rO ~v i&ov Èmvbc&cnq5 aid+mç, 6 6È KOLV~Vma&. loi Tlieaefitlrs, 17OB-lX. lo2 Thus, Kmny rem& that '[alIl the steps of the argument of 1009bl-17on be idenrificd in îhe wri tings of Aristotie's predecessors...The observation tbat things dont seem the sarne to anirnals as to us is perhaps the very oldest item in the argument Hmlitus, we arc told, said that sea is the most pure and the most polluted -ter, for fisties it is drinkaMe and saiutary, for men undnnkable and poismous (hg. 61)... Sextus tells us that becausc honcy seems bitter to somc and swcct to others, Dernocritus said that it is neitber sweet nor sou, and Heraclitus that it is M. The mntrast bas always becn especially between the SO: ... or would you maintain that each colour appean to a dog, or to any other animal you please, just as it does to you ?

THE: By Zeus, 1 certaidy would not.

çO. Well, does anything whatsoever appear the same to any other man as to you? Are you sure of this? Or are you not much more convinced that nothing appean even the same to you, because you yourself are never exactly the same? The Rotagorean assertion of the specificity and transience of the sensory perception is set forth here by Plato and Aristotle in its most universal dimension. Among sensory beings, from those exhibiting the widesi disparity to the individual subject over time. no sense impression is necessarily ever repeatable. If this is the case then it can well be argued that nothing exists apart from the perceptions of the individual subject.

While he asserts this to be the case. Rotagoras will not submit to the taunt that he has oo reasun to suggest man as opposed to any other sensory being, even tadpole, as the measure of what is. Man. through @awaoia,cm determine that certain perceptions are better or more useful than othea in the circumstances in which they are operative. What Protagoras denies, however. is that any one of these wuid be said to be truer than any derin an objective seose. Neither the number of individuals holding a belief nor the Iength of time 2 belief is held is evidence that it confers any objective validity. If the majority were il1 or mad their opinions would be regarded as true, he would argue (1009b4-6). Then again, as Socrates rernarks in the Themretur. 10-1sioce we are asleep for haif the tirne who is to say which of our confiicting impressions during the hours of waking and sleeping are the true ones? Just as it is considered necessary to differentiate @maniafrom ukûqai~,so it is equally essential that it be distinguished from &%a, as Anstotle insists elsewhere. Qavraffla cannot be opinion, he says, because this would be to infer that animais can have beliefs and although many have imagination none have opinions. [O5 It is therefore quite unacceptable, from Aristotle's standpoint, to claim. as does Protagoras and indeed Mato

--- -- tastes of the hdthy and the tastes of the sick" A. Kenny. "The Argument from 1llusion in Aristotlc's Metaphysics (T,lOO9- IO)," Mùtd, 76 ( 1967). 187. 'O3 Theuetetus, 154A. 'O4 Theuetetw, 1580. los Dc Anintu, 428a19-22. too,106 that @avta&a.is comprised of aiaûqmç and Sga. Evidence will now be sought from within the sensible itself that will demonstrate the existence of judgement independent of the padcularity of sensory perception.

Quite apart fmm the logcal objections which have already been mouoted against the contention that it is not possible to make unqualified judgements (1ûûûb2-1009a5). there are other legitimate considerations that cm dso be raised. It is, in fact, self-evident as far as Aristotle is concemed that to act on such a supposition consistently would be incompatible with ordinary life. In cesponse to Protagoras. Aristotle will make clear that it is nexessary to accept that particular consequences do predictably follow certain activities and therefore it is possible to make rational factual judgements which are independent of the vagaries of sensory perception. What Protagoras and the Heracli teans in general have been guiity of, as Aristotie sees it, is failiog to understand that the logical consequences which must necessanly follow from their daim that everything is in flux are totally contrary to what common sense would dictate.

For why does a man walk to Megara and not stay at home, when he thinks he ought to be walking there? Why dwç he not walk early some morning into a well or over a precipice, if one happens to be in his way? If, as in many cases, it is possible to determine the factors that are instrumental in piving rise to conflicting sensory opinions it is certainiy possible to establish that judgement cm be independently exercised. It would be surpnsing, for example, if anyone were to insist that an object can be characterized in te- of magnitude and colour as accurateiy from a distance as from close at hand ( 1010bS-6) when, as it may be intimated, it can be perceived more cleariy and thus give rise to a more authentic sensory phantasm. Similady, it might be questioned whether anyone should have diff~cultydeciding:

whether things are such as [they appearl to the healthy or to the si&, and whether those things are heavy which appear so to the weak or those which appear so to the strong, and those thing true which appear sa to the sleeping or to the waking. The role of ~asonedjudgement in relation to the sense appearance is quite evident when we consider those appearances which we are convinced to be uniformly false, such as the

O6 Plato, Tirnueus, 5%: Sophist. 7648 perception that the sun is one foot acms~.~~~Not only do we recognîze that with respect to the object of perception not ail appearaoces are equally true, it is also nonsense to suppose that we do not also distinguish that there are noms that are applicable to humans as perceiving subjects. As Piato has pointed out Rotagoras. in committing himself to a doctrine that al1 appearaaces are true, must accept that everything perceived by those who are! sick or insane or dreaming is also true even though "some of them think they are gods and others fancy in their sleep that they have wings and are flying." lo8 This. dthough they may say it, they cannot truly believe, to echo the sentiments Aristotle has previously expressed ( 1ûû5b28).

For obviously they do not suppose this is so; no one, certainly, if he were to suppose one night he were in Athens, when he is [in fadl in Libya, sets out for the Odeon. It is the healthy individual during their waking hours who will be the appmpriate judge of which appearance is the more likely to be tme. Those who argue that truth cm not be related either to the number of people who hold a particular belief or to the length of tirne a belief has been held neglect this proviso.

The respoose to the challenge that sensory illusion presents, as Aristotle understands it. is neither to dismiss the sensible as unknowable nor to equate knowledge with the particular and subjective. What must be undertood as the basis for an objective knowledge onginating in the sense experience is that 4avraoia can persist in independence from aXhpças the particular sense experience which gives nse to it. As Aristotle describes it, @awaoiais a movement which anses out the integrated sense experience. KOLG aïo@qor~,and is similar to it in character and content.l* It canot be maintained, however, as does Protagoras. that +mada can be equated with aïo&pç because. whereas al1 animals have atoûqcn~,some do not have bav~aoiaand it is also tnie to say that bavraoia may be active, as in dreaming, when sense perception is not.1 l0 mamaaia. as it takes up the content of the sensible, freed from its spatiotemporal materidity in the KOLV~Jul-cn~, subjects it to an instinctual ordering which, although prey to an arbitrariness most vividly manifested in madmen and dreams, is nevertheless ultimately reflective of that underlying order and universality which Aristotle sees to be

O7 De Anima, 4Bb3-4. lo8 îkaetetuir. 158AB. log De Anima, 4Bb10-15 IIo De Anima. 428aS-13 implicit in naturai substances. In fact, Aristotle argues, it is through the curnuiative experience that results as successive sensory pbantasms are reiained in memory that the underlying concepts which ground the sensible are revealed to thought and k-nth~is possible.

ïhe aniaals other than man live by appearances and memories and have but littîe of connecteci experience; but the human race [ives also by art and reasonings. Now fimm memory experienœ is produceci in men; for the several memories of the same thing ptoduce fïnally the capacity for a single experience. And experïence seems pretty mu& üke science and art, but really science and art corne to men throrigh experience.

The weakness in Rotagoras' own position is readily apparent in any consideration of the role of expert judpment in the accurate prediction of future occurrences and Aristotle finds himself in accord with Plato in the establishment of this point.

And conceming the future, as Plato says, surely the opinion of the physician and that of the ignorant man are not equaily weighty, for instance, on the question whether a man will get well or not Rotagoras mut be prepared to admit that certain individuals are accepted to possess a particular expertise and this can be effectively tested by examining the outcome of their prognosticaiions. In this connection, it is to be noted that Rotagoras in his own sphere of interest claims to be able to prejudge what arguments will prove most persuasive in court and in this he possesses a standard that cmbe factuall y attested. 1 1 It is dm a matter of record, as Plato argues, that each state enacts laws which it deems will be most advantageous to it but it is those &tes who are advised by the wiser counselIors that actuaily achieve the desired advantage. Hence, it is oot man, but the wise man, who is the measure' l2 for it is the man with the expertise who best understands the tme nature of the object of investigation. Protagoras again wiii agree that one counsellor is better than another, and the opinion of one state better than another as regards the tmth, and he would by no means dare to affinn that whatsoever laws a state makes in the belief that they will be advantageous to itself are petfdy sure to prove advantageous. As would seem now to be obviously the case, it must be alîowed that man neither seeks nor judges al1 things indflerently as he must if al1 appearances are equall y tnie and al1 men equally the measure. Such king the case an objective measure must be sought beyond the immediacy of the perception of a knowing subjat. Since al1 men do indeed make uoqualified jltdgements there must be somethîng extemal to the immediacy and subjectivity of the çensory perception which is, itself, the object of desire and action.

For he does not aim at and judge aU things alike; when thinking it desirable to drink water or to see a man, he proceeds to aim at these things.

The sophists in discerning that the sensible is first ordered to the intelligible through $anada have doubtless been responsible for a significant advancement in philosophic thought. Their predecessors. the natural philosophers, in conceiving of sense knowing in tenns of physical alteration brought about directly by sensation, remaioed adherent to a conception of king thal as Aristotie sees it, left these thinker in a state of perplexity from which they were unable to escape. However, although Protagoras has ken able to free thought from i ts Re-Smtic hpiaby bringing sensory perception under the ordering principle of the intelligible, he has been unable or unwilling to disentangle it fmm the direct ties that bind aioû~lcnçand @ama&a in their particularity and as a result is firmly entrenched in an kopia of his own. The destabilizing of Protagoras' position that 'al1 appearances are tme'. with the establishment of objects of thought which persist apart from the conception of the individuai perceiving subject. leads Aristotle to turn from the consideration of the self-conscious awareness of sensory experience to an examination of the act of sensation itself and Protagorasr further assertion that 'nothing exists apart from the perception of a knowiag subject'.

Sensible objects erist apart from the perceiving subject (10 lob14- 10 1la2) It is in the recognition of the power of human subjectivity as the unifying centre of the sensible that the strength of the sophistic position resides. Rotagoras has found for the first time a inroreip~vovwhich can can enfold the many within a pnor unity. The weakness of his position, as both Plato and Aristotle recognize, is that it is a unity which is itseif always in process, not capable of holding in a single grasp the king and non-being of the sensible in its contrariety. Ptato, himself, as Aristotle sees it. has moved beyond the position of Protagoras to recognize that the= must be a Ulroreipmov which is fully comprehensive of kingand not-being so that the change is not fmunmusicai to musical but fmm unmusical Socrates to musical Socrates. What Plato is unable to show, is how that connection which is there for the knowing subject is an integral component of the sensible object. Aristotle has aiready remedied this deficit to his own satisfaction in bis account of sensible change. Now the task will be to show how the stability underlying sensible change is revealed through sensation, for if it can be established that there is a sensible ~alityextemal to the knowing subject then Protagoras' claims will be refuted.

Sensation of the proper object of a sense is mot false (1010b14-30) AU aspects of sensation are not equally authoritive and this must be undeatood to be the source of the common misapprehensioos conceming the reliability of sense perceptions. It is, in fact, only in relation to its own special object (IGiov) that a sense power can be said not to err.

And again in the case of sensations themseives the sensation of what is alien and of the special object of a sense, or of what is a related object and of what is its own object, are not equally authorïtative- The specid object of a sense is that of which it is uniquely perceptive as, for example. sight is receptive of al1 colour so hearing is receptive of ail sound, and touch of al1 that is tangible. Whereas each sense is fully comprehensive of the range of qualitative contrariety within its own field of being its power cannot be extended beyond this to determine with the same degree of reliability where or what the sense object is.1 l4 Aristotle lays particular

stress upon the vericidal nature of the relation betw een a sense power and its special Object so that in the case of colour it is sight and not taste which will have the authonty while the reverse will be tnie in the case of flavour ( 10 IOb 1617). However, i t must be understood as implicit in this clairn that the sense power is operating within its normal range of activity. As a power in a material sense organ, the sense power is itself destmctible, capable of operating only within certain lirnits.' '5 Sight, for example, even when the organ itself is

l4 De Anima, 4lûal416. Plato aiso makes the point that abjects perccived through one scnse wnot be penxived through another. TIaeae~etxu*185A. li5 De Anima, 424a3û-31. healthy, can be overtoaded by bright light and so not function properly in the detection of colour and it is obvious it will also be affected by considerations such as a lack of light and the distance between the subject and the object. Such factors as these Aristotle expects to be incorporated into any judgement as he makes quite cl- (1010b4-11; 1063al-5).

Those followers of Heraclitus who suppose that something can be at the same time 'so and not so' have aiready been shown the logical hpossibility of maintainhg this supposition with relation to being, in r4. Nor, as it now seems, can they argue that as being appears to our senses it is both 'so and not so' for it is impossible that a sense organ perceive something that is its proper object to be at the sarne, for example, both sweet and bitter.

Each of these [senses] never says at the same time concerning the sarne thing that it is 'so and not so'. It is possible to go further and to argue against Rotagoras that not even at different times does a sense disagree about the essential nature of the quaiity it perceives For example. the same wine may taste sweet to me when healthy and bitter when I am sick or the condition of the wine may deteriorate causinp it to differ in taste. Nevertheless, Aristotle states, when considered in isolation from its inherence in an object or its perception by a subject, there remains an essential conception of sweetness. This essen tial qualitative nature of sweetness is such as it is by necessity and consequently never changes and we cannot be mistaken about thk (1010b24-26). Al1 those who claim that things are both 'so and oot so' destroy this necessity and by doing so, he reaffirms, in accord with his earlier concIusions ( 10Maîû-22),they elhinate substance and essence.

And indeed this is eliminated by ail these accounts, as nothing has a substance so thus there is nothing of necessity. For it is not possible that that which is of necessity be in this way or that, so that if anything is of necesssity, it will not be 'so and not ço'.

The sensible world has a reality apart fkom sensation (1010b30-1011a2) This is the point to which Aristotle has been shaping the argument. Agahst the views of those who would deny that anything can be of necessity he has established the being of qualitative essence which cannot be both 'so and not so' (10lOb29-30). Now it can be asserted that quite apart from the individual perceptions of a knowing subject there are recognized certain unchanging qualities which are the proper objects of the organs of sensation and accurately identifiable by them. However. while form has been established through the preçence to the sense organs of the logcal contraries, there has as yet been no recognition that there is anything in the sensible that underlies these contraries as a hrei~vovwhich is self existent. There must. in fact, be something that exists apart hmwhat is immediately perceived in sensation, Aristotle argues, for if that were not the case. then nothing wodd exist if there were no sensing beiogs. While one could certainly argue that there would in this case be neither sensations or sensible qualities which are affections of the perceiving subject ( lOlOh32-33) thïs is not to deny that the source of these affections would thereby cease to exist. There must be, as far as Aristotle is concerned, things which are objectively existent and potentially perceptible. quite apart from the activity of sensation. 1 l6

And it is not possible that the substrab which cause the sensation would not exist apart from sensation. For sensation is not of itsel f but there is something other beyond the sensation, which must be prior to the sensation; for tha t which moves is prior in nature to that which is moved. Reflecting upon Aristotle's response ( 1010b 1- 101 1a2) to the argument presented at 1009bl-12 on the 'tnith of appearaoces'. it can be concluded that the sensible world does exist apart from the perceiving subject and that the qualitative nature of the sensible object i s received trul y by the appropriate sense organ under normal operating conditions. so that qualitatively the world is there for the sensing subject In establishing how the extemal sensible world is taken up by thought, however, it must be recognized, as Plato points out, that the very fact that we acknowledge the operation of the sensory powen as "each different from the other and the same as itself" provides a reflection that is different from mere sensation. 17 While each of the five senses has a completeness in its direct relationship to its special object this is not. either for Aristotie or Plato, in itself sufficient to account for the sensory perception.

l6 As AIcxandcr rcmarks, "the senscs do not corne to be [am]of themselves. but rather of dn subjects, and sense pception is not the cause of their king subjects; on the contrary these things are beings in their own right, and mus&as subjects, pre-exist, in order tbat sense perception may be able to apprehend them,' Alexander of A phrodisias, 3 16.22-25. H7 Theaeterus, ISAB. SO: Yes, for it wodd be strange indeed, my boy, if there are many senses ensconced within us, like warriers in the horse at Troy, and they do not ail unite in a single nature, whether we shouId caii it sou1 or something else, w i t h which we perceive, through these as instruments, the objeds of perception.

The sensible world is not sirnply an agglorneration of unrelated qualitative perceptions for there is a unity and integrity that underlies and connects them. For Plato, this unity lies in the activity of the thinking sou1 as it contemplates through its own iostnimentality the common ternis (the Foms) which relate and divide the input from the various senses; as far as Hato is concerned, there cm be no integrated sense impression in the sense that Aristotle understands it at the level of the sensible. 1 l9 Protagoras, by contrast, recoe~zesno commoo terms, the perceiving subject througb 4avraoia. in its specificity and transience, is the sole detenninant of the 'unity' and 'reality' of the sensible. Aristotle has recognized the necessity to carve a path between these opposing positions if the sensible as such is ta be a source of objective knowledge. It is not in the intellect but in the 'common sense'. the KOL~S~GIÇ, Aristotle argues, that the motions arising fmm the activities of each of the five senses corne together as a single sensory input. With the conception of a subject as a unifying centre there is at once a focus of perception in which resides the potentiaiity for intelligibility as qualities are sensed associated with objects which have shape, size, and oumber, revealing a sensible wodd in space and time. At the same time, it is necessary to maintain in response to Rotagoras that it cannot be said that al1 appearances are simply subjectively me and that 'man is the measure'. It must be recognized that it is in the incorporation of quantitative data in the formation of the inte-pted sense impression that those illusions that diminish the authority of the sense perception rnost cornmonly aise and it is here that the origins of the diversity noted at 1009b7- 12 must therefore be sought. Knowledge of the sensible is noi unremittingiy subjective but it is irnperfectly received. Fom is there in the sensory phantasm but, although liberated from the extemality of space and time, it still lies hidden, encrustecl in the accidentai and contingent no

TheMtetw, 1&D. l l9 Codord in cornmentating on differenas in the understanding of rorva in Plato and Aristotle. points out that "Piatodoes not speak of a 'common sense' (ICOL*aidqarS), but on the contmy insists that his common tenus are apprehended, not by sense, but by thought. The judgmcnts invoIving them rirc made by the mind, thinking by itsclf, without any specid bodily organ. The tenns are 'common'. not in Aristotlc's sense, but in the sense in wtuch a name is common LO any number of individual things. Thus 'cxists' is 'applied in common to al1 Ùiings' (~otvbvfrxi Kâar), [Themtetw],185C. F.M. Cornford, Plab's Theory of Knowledge (London: Routldge & Kegan Paul, 1%O), 1O5 l 2o Green dcscribes Aristotle's psirion well. "1. us... knowledge is developed throua the action of sensitive organs. These indeed can of themselves give no knowledge apart hmthe distinguisbing and EVERYTfiING CANNOT BE RELATIVE

There can be no dtimate criterion of judgement (1011a3-14) From the account in r5 it has emerged that both knowing and king, in the form of judgements and objects of judgements, must be admitted to exist apart from the subjective detemiimitions of an individual perceiving subject. Aristotle can now return to pick up the thread of the discussion on judgement introduced at the end of r4. Even allowing as they must that there are judgements extemal to aioûqolç, there are still those who will go on to rai se the further question of how an ultimate cri terion is to be established in the case of codicting judgements. How, they will demand to know, is it possible to say who has judged rightiy in the case of who is the healthy man and on a variety of other questions ( IO1 la4-6). In response, Anstotle can but point out as he has earlier ( 1006a59), that in pressing this issue these people show a want of education for "they are seeking a ceason for things for which no reason is possiblen (101 la12- 13). To argue thusly is to incur an i6nite regress and ihis is unacceptable, as has been repeatedly pointed out., The beginning must be with something meaningful, a ,psp of the indivisible as what is and is one.

In so far as it can be said that in both thinking and perceiving "the soui discriminates and is cognizant of something which isn,121 it is possible for Aristotle and Protagoras to agree. However, whereas Rotagoras confines what is to the immediacy of particular judgement, conflating 6.inhm and aio&laç, Aristotle maintains, as he elsew here rnakes clear, that thinking and perceiving have separate objects and just as the sense in act has been declared to be identical with its proper object so du, is the intellect in act iden tical with its own object. Mind must be related to the objects of thought in the same way as sense is to the vg& 122 It is through the activity of vhorq, Aristotie maintains, that the universal foms that lie hidden within the sensory phantamis are revealed as the proper objects of thought. No independent proof cmbe constmcted for the undivided cornmon notions which. as the proper objects of intellecf are ppedintuitively without emrand provide the indemonstrable starting points of demonstration. unifying self which rnakcs them its vehicle. Except in relation to this self, their 'reports' arc in the strictest sense unmeaning, for thcy present things cither in mere deiachment or mmcontinuity. Yct acting through them i t is subjcct to a neccssary delusion, the continued ternoval of which...g ivcs an essential chancter to human knowtedge as at once imperfect but thnnigh its imperfection progressive" T. H. Green, Worh of lhmtzs Hill Green. 3d. ed. v3. (New York: AMS h,1973). 73. * * De Anima, 427a20. 22 D, Anima, 42%13-18. And so thinking of the indivisibks is among those things concerning which there is no falsity, but in those things in which there is falsity and mith there is already a synthesis of thoughts so that they seem to be a unity. Just as in sensation the proper object of a sense power is iofallibly perceived so too is the &OS, as the pmper object of the intellect received without error. It is in the subsequent combinations and dissociations of these ideas that errors arise.

Assertion is of something about something, just as is negation, and always is eithcr true or false. This is not so with al1 thought: that [thoughtl of what it is according to its essence is true but it is not an assertion about something. Just as sight is hue for its special object but if the white object is a man or not is not always true, so in the same way it hoIds for those things which are without ma tter.

Throughout his examination of those beliefs found associated with the Protagorem contention that 'dl appearances are tme' Aristotle can be seen to be working from within the context of the argument of the Theaetetus. as together he and Plato present a united stance in the pusuit of a common foe. The problem of 'the place of the forms' and of whether and how the objects of thought and sensation can be brought into relation with one another will emerge as a major issue outstanding behueen them but it will not be addressed here. Perhaps, in putting to one side temporady an issue undoubtedly of inestimable importance to him, Aristotle is respoading to the kind of considerations Plato himseff had already expressed. So it was that, despi te the recogniziog the importance of finding a way between the oppsing lines of the rnaterialists and the idealists.lZ5 Plato declined to take up the Eieatic position for discussion in the Theaetetus on the grounds that so large and important an issue, if it were to be treated effectively. would compietely ovenvhelm the ongoing argument. In particular this subject we are now raking is of vast extent. Examined as a side issue it wodd be treated unfairiy, if given sufficient attention the discussion on knowledge would be pushed aside. Only when the self-explanatory inadequacy of the sensible has been thoroughly exposed will the challenge of the sophists be satisfactody repulsed and only then can thought. rel eased from the tentacles that draw it back into the flux, move forward to consider the nature of intelligible reality.

The donthat 'ail appearances are hue' must be qiulified (1011a17-bl) Those who perskt in claiming unequivocally bat everything is 'so and not so' caanof in fact, be effectively refuted on their own ternis because inherent in their daim is the nght to be ailowed to contradict themselves. As has been amply establishd in r4, ihis makes any meaningful discourse with them impossible. if they are serious about being convinced by argument and willing to be held accountable they must agree to a refining of their position. There is no longer any question, as far as Aristotle is concemed, that the PNC mut be acceptai as a universal law of thought forming the basis for any rational discussion. The ramifications of the assertion that 'al1 appearances are me'have been explored in TS and it is now time to draw upon these conclusions in a final refutation of Rotagorus. Inherent to the Protagoorean position is the notion of relativity and it is on the consequences that must flow from this stance that Aristotfe focuses his critique in r6. Since whatever appears is an appearance to someone, he points out, the argument that al1 appearances are true makes everything relative to a particular perceiving subject (10 1la 17-20). However. before pmceeding to a specific refutation of the relativistic position, the sensory perception must be further examined in order that its nature be defined more precisely with respect to the contradictions which have eariier been noted to stem frorn variances in sensory impressions (1009b7-12). In light of what has emerged from a consideration of the complexity of the sense impression (1010b14-26), the problem may now be restated in such a way that it is possible to avoid fdling into that abyss of self-contradiction that so confounded the natural philosophers. What must be seen to be the case is:

that it is not what appears that is, but (1) what appean for him to whom it appears, and (2) when and (3) to the sense to which,lf7 and (4) under the conditions which it appears.

27 Ros, ANto!lels Metaphysics v. 1. wtes loc. cit. thai j uarslaied as Zo the seme io which it appearsï is in accord with the structure of !he argument as ii appears at 1010b14-19and 101 la34 Inarguabl y, ( 1) Rotagoras, in asserting that 'man is the measure' has appropriatel y identifieci the individual perceiving subject as of central importance in the determination of the nature of the seme impression, as Aristotle here recognizes. It mut also be accepted. (2) as Rotagoras would contend, that the sense appearance is not only particular but transitory in nature so that what appears at one time to be the case may not be so at another. In addition, (3)each individual sense impression. even as i t presents. may well provide seerningiy contradictory data but this must be seen to result from the cornplex nature of the sense impression itself. What is received by a human subject in aioûvpq and formeci into the sensory phantasrn must further be subject to the judgement of intellect. Thus, Aristode has argued that where there is a confiict between the special object of a sense and that which is perceived incidentally it will be that which is the appropriate object for the sense that will be deemed authoritative (1010b 1517). So. for example. when an object appears to the sight to be honey but not so to the taste (101 la2627). it will be taste as having the authority in the case of Ravour that will be judged to be correct.

That a sense power is unequivocal with regard to its own specid object ( 1010b 19) is a fundamental tenet of Aristotle's account of sense knowing. Certainiy it is the case that things may appear different to each of our two eyes but the cause of this must be looked for in a defect in the sense organ itseff. i.e. eyesight ( 10 1 lm-28). and should not lead to the conclusion that the thing is both 'so and not so'. Even when the sense organs are healthy. the conditions (4) under which a perception presents may give rise to error. For example, Anstotie notes the case in which when our fingers are crossed sight sees only one while touch recognizes that there are two (101 1a33-34). What is essentiai to reiterate is that in al1 cases such apparent contradictions are resolvable by a thorough analysis of the conditions pertaining to exh sensory perception. So that when it appears that somethiog is 'so and not so' it will on examination reveal:

but not to the same perception and in the same part of it and under the same conditions at the same time (101la34-102 1bl). What Aristotle is now confïdentiy asserting, and in very much the sarne terms as he postulated at the outset of this whole discussion( 1005b17-23). is that the PNC cannot be flouted so that when contradictions are apparently present the reason must be sought in the conditions under which the perception is sensed. The kopia that gives rise to the apparentiy contradictory nature that swse appûaraoce presents for knowing has been resolved into its elements. On the one hand, as argued in r5. objects exist apart from the immediacy of sensation and objective hue judgements can be made conceming them (1008b21-23). On the other hmd, what appears to each individual to be the case. in the immediacy of sensation is also true. However, associated as it is with a multitude of interacting parameters, this 'tnith', Aristotle would argue, is limited to the particular and contingent. Thus, ali those who adopt the position of Protagoras must modify their stance and say of what appears. not that 'it is true' but that 'it is true for this man' at this instance in time and under these conditions.

The perceiving subject is not the came of the the sensible (1011b4-7) Those who join Protagoras in claiming that dlthat appears to a perceiving subject is true for him make al1 things relative to individual perception and opinion with the result that objects ody exist when they are perceived or opined by someone (101 1b5-6). It has already ken argued that sensible objects exist apart from the perceiving subject ( 10 10b 14- 101 la2). Now Aristotle rejects outright the daim of Rotagoras that it is the individual perceiving subject who, in taking up and ordering to himself the content of the sensible, is the very cause of its being. If it can be established that things corne to be irrespective of whether or not sorneone has first thougbt that this would be the case then not ail things will be relative to individual opinion and the position of Protagoras that 'man is the rneasure' will be refuted (101 lb6-7). This point is not argued further by Aristotle here, no doubt because the implications of ernbracing such a position are so patently untenable. Alexander points out some of the more obvious incongniities which would ensue. for example, "it is absurd to say that a war or a flood or an earthquake would not have come to paspass.if someone had not first opined that it would occur." IZ8

If it is admitted, as must surely now be rationally conceded, that not al1 thinps are relative, then it follows that not al1 a person believes will necessdy be bue. Aristotle has earlier relied, as did Plato before him, on the predictive value of opinion in order to undermine the Rotagorean position. The argument that not al1 men are equally the judge of what will corne to pas resulted in the recognition of the expert opinion and the concomitant establishment of judgement as an objective form of knowing (1010blL-14). It is the strategist, seismologist, or climatologist, respectively, who will be the one most able to predict whether war, earthquake, or flood are imminent. Now Anstotle using the same argument bas tumed from the side of the knowing subject to the side of being. In the sensible world knowing and king are inevitably held apart by material potentiality and so

'28 Alexander of Aphrodisias, 322,38-39. Alexander. with &viocs relish, cxpounds a num ber of additid arguments which revd the 'myiiad absurdities" that ensuc from an argument that makes ail things relative, 326.1 - 19. the judgement of noue of these experts is infallible. The extemal world, however, will make its objective presence felt, and forcibly so at times, quite irrespective of hurnan judgement. With this assertion of its own extemal reality, an objective fom of king independent of the relative perceptions (1010b33-101 lal) and opnions ( 101lh6-7) of the individual, a world of sensible substances cornes once again into focus.

The refotation of Protagoras reveals the nature of the relative (1011b7-15) To complete his rebuttal of Rotagoras, Aristotle now mounts a direct attack on the concept that dl things are relative. Yet even as he doaso, he can be found to be carefully structuring the argument to draw from within this final refutation of Protagor.~the necessity for the recognition of his own categorical understanding of relation. This, in i ts turn, will lead quite natudly to an investigation of the nature of logid contrariety as the relation between form and its ozÉpr\arg; and from this it is but a short step to the consideration of the nature of non-being as relative, Siwap~npoç n. Thus, moving within the logic of his owo metaphysics and following the same progression used to establish the nature of 'this science' in r1-3, Aristotle introduces to the discussion on relativity, the concepts of limit, a determinaie nature, and prionty, concluding this section with a reaffimation of the universal applicability of the PNC.

Rotagoras' position is completely comprornised, Aristotle argues, by an inadequate undentanding of the nature of 'Relation'. Fintly, if anything is to have an identity, the number of correlates it has cannot be indefinite but must have a limit (101 1b7-8). As Anstotle understands if the indeterminacy of the sensible is first subject to bitthrough the relation of contrariety . Correlative relatiooships, Aristotle argues, are always specific and w hen properî y defined each correlate is referred on1 y to i ts own particular deteminate converse.129 Where, for example. the same thing can be said to be both a hdf and equal its relation to the double is not as equal but as half (101 1b89). That it is possible, nevertheles, for the same thing to be both double and half is a seemingly contradictory notion, one which set the head of Theaetetus spiming, for intuitively mind knows that nothing can become greater or less without being increased or decrea~ed.~~~Yet, according to Protagoras' theory, it cm be argued that since Sirnmias appears shorter than Phaedo and at the same time taller than Socrates it must be the case both that he is taIl and he is short. What confused Theaetetus and has not been -0rasped by Protagoras is that it is not the relationship of the attributs themselves but the comparative relation of one subject to another with respect to a paiticu1a.r attnbute, such as size, that musi be undentd. A11 these things, Aristotle says, are to be explained by derence to sornething to which they belong, and not in any other way, &a yàp rà eipilii~MaWÙ kpk&v Espmv eivm Àéyerat rai oUr ÜUo n. 13'

Whereas it is certaidy possible for a thing to be attnbuted a haif and double. or ta11 and short, it cannot be so in relation to the same subject Hence, Socrates is not short by nature but is so coincidentally. Thus, it might better be said, not that Socrates is short, but that in relation to Simmias or to Phaedo, Socrates as hou~ip&vovexhibits the property of shortness. Rotagoras, since he bas no way of uniting the king and non-king of the sensible in a unity that is pnor to their difference, cmoffer no such )i6yo~and hence must inevitably faIl prey to contradiction. For the most part correlatives do corne into king simultaneously in the act of perception, as do the double and the half, Aristotle concedes.~32but this daim cannot be extended to the objects of knowledge and perception as Rotagoras supposes. For both knowledge and perception. Arktotle argues in the Chtegories, the object is prior to the act of knowiog or perceiving.

Ço that when the objed of perception is taken away so is the perception. But taking away perception does not take away the object of perception.

In making dl things relative, Protagoras, in the final analysis must inevitably eliminate even his own existence, as Piato recognized, for neither the perceiver nor his perceptions cm escape the al1 pervading Cratylean flux. 134 Based on his analysis of Relation, Aristotle takes up the same point, reinforcing from a logical perspective Plato's conclusions. That which thinks is said always in relation to that which is thought, but these correlatives are not equivdent in the way that are, for example, equals. 135 Within this reiationship one correlate is logicall y prior.

If, then, in relation to that which thinks, man and that which is ttiought are the same, man will not be that which thinks but that which is thought,

I3 ' Ca.6b3-5. i32 Ca.7bl5-18 133 Cal, 8rt3-4. 134 Theaeferw. 182DE '35 .For that which opines and th which is opined are not among beings which are relative in this way; for. if this were the case, then everything which opines wodd be, in tum. the same as that whîch is opine4 as equd is cqual to the equal. and Ii ke is to li kc.' Alexander of A phrodisias, 324.3 1-34. According the Rotagorem theory of relativity nothing exists unless it is thought by man to do so. If this were redly to be the case, man's own deking would be as an object of thought and since king thought is different from its converse, thinking, man would not be that which thinks but that which is thought. Men man is thought to exist he will exist but, if 'being thought' is made prior to thinking, what is potentiai is made pnor to wbat is actual and so dtimately, from Anstotle's perspective, there can be no sustaining cause of thinking and thus no existence. For Rotagoras' world to be conceivable at al1 it requires that independent and prior actuality which for Aristotle is Notw,

Even allowing that it would be possible under Protagoras' tems for man to exist as that which thinks, his assertion that 'man is the measure of al1 things' relates man. as thinking subject, to an indefini te num ber of specifically different correlatives, ei 6' E~amov Esrai xpk rb 6~a~ov.npk kipaEmai r@ ei&i rb wacov ( 101 1b 1 1- 12). To accept this to be the case wodd be, in effect, to abolish al1 definition, by eliminating substance and essence and making dl things accidental. Potentiality has corne once again into view and with it the problems Aristotle sees to arise when non-being is considered as indeterminate othemw. ETEPOV. An understanding of the tme nature of the relative, as both determinate and ordered to what is prior, is intrinsic to the conception of privation, ~Éprlcq,that Anstotle is about to introduce into the discussion. If non-king is to be brought into a meaningful relationship with king it must be as 6iivapq xp6~n in a limited and determinate relation to fom as that which is prior.

In identifying a centre of consciousness in man, and in recognizing that thought can be potentially al1 things, Protagoras has identifieci a inro~~i)<~vovfor king in the intelligible and provided the needed impetus for thought to extricate itself from its sensible entanglement. At the same time, however, in making al1 things relative to that individual self-consciousness, Protagoras has obviated the necessity for any independent objective reality whether intelligible or sensible. While PIato rnight argue that Rotagoras fails by not withdrawing thought fully and objectively €rom its particularity in the perceiving subject, Aristotie wouId contend that it is in failing to recognize that the king of man is not to be identified with vo* but with substance as the dvokov, the composite of matter and form, that Protagoras has erred. On either account, his phiiosophy has been found wanting, collapsing inwards upon itself under their combined assault With the finai refutation of Rotagoras' daim that al1 opinions, and hence aIi contradictory statements, are at the sarne time tme, the lengthy argument in support of that most indisputable of al1 principles, the PNC, bas been brought to a conclusion. The PNC which found its first and primary expression and exposition as a logicai principle of substance ( lûû6a29- 1007b 18) has been shown to witbstand the assault of the sensible flux and emerge as the unassailable ground of our cognition. It can now be stated-

that the most firm klief of aii is that contradictory statements cannot be at the same time true and what the consequences are for those w ho say this and why they say this.

Contrariety is a determinate privation (1011b15-22) The confusion that resulted for those who from the flux of the sensible were led to the conclusion that al1 appearances are true (100% 1) has now been dedt with to Aristotle's satisfaction. However, refiecting upon those concerus which amse for natural philosophers, such as Anaxagoras, from their observation that contraries seem to corne into existence from the same thing ( 1009aS2-28), he recognizes a need to further clarify the nature of potentiality by pointing out the relation of contranety to the now established Iogjc of non-contradiction. Just as contradictones cannot be true at the same time of the same thing so is it likewise impossible for contrary attributes tc belong to a subject at the sarne time (101 l b1618), Aristotle maintains, for contrariety is a kind of contradiction ( 1-3- 4). Taking ioto account the recent discussion on the nature of the relative, Aristotie can now assert that one of each pair of contraries is a privation no less than a contrary, r6v @v yàp évkov Bk~povdprlai5 Éonv okhov, (101 1blS 19). The deteminate relation between form as what is prior and its privation, matter as posterior, introduced in is fundamental to the nature of contranety, as Aristotle understands it ( IO5%33), and will assume importance in l7 as he considers further the problem of potentiality and the dation of contrariety to contradiction. With the assimilation of contrariety to the logic of non-contradiction Aristotle's intention that the PNC be extended to encompass the whole of reaiity, briefly indicated early in the argument (1005b2628), is also reafinned. The PNC is to k considered fuily applicable, not only to the delineation and definition of substance and essence in a logic of non-contradiction, but also to the universal attributes of substance in their logical contrariety. As it affirms and denies, the intellect captures the logic of substance and its attributes and so one must conchde, Aristotle says, that:

if it is impossible to affirm and deny truly at the same time it is also impossible that contraries should klong to a subject at the same time, unless both belong to it in particuIar relations, or one in a particular relation and one without qualification. POTENTIALITY IS NOT INDETERMINATE

The focus of the discussion oow tums to the PEM. as Aristotle continues to pick up the thread of an argument which saw him earlier conclude that al1 his opponents, whether Heracli tean, Rotzigorean, or Anaxagom. are forced as the logïcal outcome of their position to say that king is potential(1007b 18- 1008a2). ai yiyvarar &ijTO .roû 'Av~ay6pauT &oc ~cka~p+a.ra- k pq8b &Aq0& inuip~erv( 1007bB-26). And thus we get the doctrine of Anaxagoras, that aH things are mixed together; so that nothing exists in reality. To accord potentiality an ontological independence. intemediate between king and non- being as contradictories, is to fail to detect its proper significance, Aristotle will argue. As he continues to prepare the gound for the full development of his own theory of potentidity and actuality, it is of paramount importance that Aristotle dispel any misconceptions that may undermine a pmper understanding of how beiog and non-being cm combine io make change possible. As a result it is necessary that a close scrutiny be @ven to the consequeoces which follow from an incomplete understanding of how it is that king can be said to be intermediate.

The starting point unequivocally must be with definition. for unless something meaningftd can be said. as has already ken argued in the extended examination of the PNC. there can be no rational discourse. The logic of non-contradiction is now the accepted point of departure. nothhg cm be simultaneously 'so and not sot and. therefore it is impossible for the objects of the intellect to be truiy afimed and denied at one time (101 1b2G21). What is important to further establish is that the logic of non-contradiction is also a logic of necessary and reciprod disjunction. in the form of the PEM. so that something must ei ther 'be or not be' what the definition entails. That tmth and falsity are the only values that can be assigned to any judgement, AristotIe iakes to be the self-evident basis for his argument and from this there arises the definition of tnie and false.

On the one hand, to say of what is that it is not, or of what is not that it is, is false, and on the other, to say of what is that it is, and of what is not that it is not, is true. Tnith and fdsity lie not in the object itself but in the connections that the intellect makes when it joins subject and predicate in affirmation or denial of the king or non-king of something. There is no middle term between tmth and fdsity so that "the one who says of anything that it is. or that it is not, speaks either what is true or what is false" (101 l 1b27- 28). '36 Those w ho suppose that there can be a middle temi between contradictories impt y thereby an intemediate behueen king and non-being, something that is neither true nor false. This Aristotle sees to be Anaxagoras' expressed position, for in saying 'dl things are mixed' he is claiming tbat there is something which is intermediate between contradictories and neither is nor is not The structure of redity, however. is reflected in the laws of ihought for tnith is ordered necessariIy to being-137 Sioce there is no intermediate between truth and fdsity neither will there be one between king and non- beiog. It can be concluded, therefore. in support of the PEMand against Anaxagoras and al1 those whose position can be equated with his, that something either is or is not.

Contrarietg is distinguishable fmm contradiction (1011b29-1012al) It has been pointed out that contrariety is a kind of contradiction in so far as al1 contrariety is privative (101 l b 17-20). However, contradiction and contrariety must not be supposed to be identical. It is, indeed, through a confiation of the the logic of contrariety with the loge of contradiction that Anstotle sees that al1 his opponents, Ptato included. are held fast by their hpia,unable to delineate non-being as 86vapiç rrp& n fmm non-being as É~pov.Pursuhg this point from the perspective of the logc of non-contradiction and the PEM, he now points out that there are, in fact, two ways in which an intemediate between contradictories w ould present iiseff.

lndeed, the intennediate between the contradictories will be so either (1) in the way in which grey is between bIack and white, or (2) as that which is neither man nor horse is between man and horse, The latter kind of intemediate cm be quickly dismiued as a purely artificial and chance association, as rose can be said to be intennediate in the sense that it is at the sarne time both not man and not horse, given that no relationship of logical necessity comects the three objects. Truc intermediates are of the former kind as grey is between black and white, and are always associated with the process of change- Change, Aristotle says, occua only between contraries for there is no change other than into opposi tes and that

136 Ross rem& that 'the opponent is assumed to admit (a) the co-mess of the definition of mth and falsity, and (b) that every judgemcnt must be either meor false. Thus Aristotle is infemng the rnetaphysical form of the law of the excluded middle-that them is no objective intemediate kween contradictories-from the Iogicai form. The argument thus has vdue ody ad homNwrn-But of this Aristotle is weli aware; he knows that first principles cannot be demonstratcd" Ross, Aristotle's Meurphysics v. l,~%4-285note 101 1bB. 13' 13' Aristotle's understanding of the relation between the structure of king and the laws of thought was estdished dierin connection with tbe PNC. which is intermediate to them. où yap Sem p&rafhXfi 0iA1: 4 E~S~à hmu~ipzva rai pz* ( 101l b33-35).

Although contraries, such as black and white are necessarily associateci through sharing a common Vnom+zvov, white cornes uot from its contrary, black, which is itself a form, but from its contradictory, what is non-white but white npoS m. Orte of each pair of contraries is seen by Aristotle to be always privative in relation to the other and privation is the deniai of a predicate to a determinate genus, ii 6È dpqoiç chw& Ècmv air6 nvw p~&vou y&- ( 101 1b 19-20). As privative, in its denial of a predicate it is 'other'. but as determineci to its essence, 66wxpq & n, it is 'same' both potentiaily and actually.

For there is no other cause of the potential sphere's becoming an actual sphere than that this was the essence OC either. It is in this way that contrariety as privation, non-king npoS n,differs from contradiction in general, non-king as B~~pov,and that Aristotle is thus able to exteod the PNC to the whole of sensibfe reality. Although contradiction never admits an intemediate, privation sometimes does as when a man may be said to be neither good nor bad ( 1055b23-24), or grey may be said to be in between black and white. Nevertheless, the intermediate is always in pmcess of change between the extremes, and it is as qua not-white that grey as intemediate is said to change to white. If there were any other sort of intemediate between cootradictories there would have to be a change to white which was not from not-white as privation and this, Aristotle asserts, is not in fact ever seen (1 01 1b3H012al)-

There can Ibe no intermediate between contradictories (1012a2-17) Ancillary to what has dready emerged as central to a discussion of the siflicance of the PEM. further logical objections can be brought to bear against those that maintain that it is possible for something to exist that 'neither is nor is not'. It is important in this connection that the argument be seen as confined to contradictories exhibiting a logic of 'same' and 'othef, in which negativity is expresseci as sirnpl y E~&pov.and not to be equated with the logic of privative contradiction which Aristotle sees to be the basis of a solution to the problem of how king and non-being can be said to combine. The bnef and cryptic presentation (1012a2-16) is now reliant on an acceptance of Aristotle's own conception of reality, the doctrine of substance as he has developed and defended it in Book T. From the definition which is the basis for the argument (101 Lb2529) it is evident that the intellect works on a logic of tme or false so that everything mut be either affirmed or denied. Anything that cmbe an object of reason or thought. Giavqbv ai vqsov. is subject to affirmation or denial and it is in the rnanner that the intellect makes the cmnection in which truth or falsity resides (10124-5). Conversely it must be the case, for Aristotle, that what motbe the subject of a judgement by thought is what absolutely cannot k and so will not therefore be an intemediate form of existence-

If the PWM is to be displaceci as a universai axiorn by a counterprincipd of qua1 authority and we are notjust arguing for the sake of argument an intermediaie must be postulated betwem al1 contradictories (1012a5-6). From this it would follow that a man could say what is neither tnie nor untme and this in tuni would be dective, at the most universal level, of a kind of king which oeither is nor is not, which is. indeed. what Anaxagoras proposes. To admit this. however, is at the same time to posit at the level of substance that there will be a kind of change besides grneration and destruction. &TE ai mpà y&v~aiv rai 4ûopàv ptaf5oXfi ris èûmr ( 101îaS-9) Since the generation and destruction of substance are, for Anstotie, aspects of a single integral and instautaneous activity in w hicb the 'coming to be' of one substance is the 'passing away' of an0ther.13~the interposition of an intemediate between generation and destruction is incompatible with the essentid nature of substance as the unchanging pund of the sensible. Hence, Aristotle cm conclude that by their very nature tnith. being, and substance, must in accord with the logic of the PEM, excfude an interniediate between themselves and their contradictories.

The refutation of the contentions of those asserting that there can be an intemediate betw een contradictories cmbe furthet extended through an examination of those classes of things which possess accidental attributes which as contraries are at the sarne time coextensive witb their contradictories.

In aU classes in which the negation of an attribute involves the assertion of its contrary, even in these there wiU be an intermediate; for instance in the sphere of number there will be number which is neither ddnor not-odd. But this is impossible as is obvious hmthe definition. Odd and even by their nature as contraries are reciprocally exclusive of one another.139 Since the corresponding contradictories, not-odd, and not-even, are readily identifiable as

138 De Gam., 319a4-8 139 Aristocle's position is chat when a subject must contain one or ihc other d a pair of mntraries intermediaies are never found. When rhere is no such necessity they wilI always have an intermediate. Ca-. 12a 1-2.. cwxtensive with even number and odd number, respectively, it is irnmediately apparent that just as there can be no intermediate between the contraries, even and odd, neither can there be one between the contradictories, odd and not-odd or even and not-even.

Io any case, Aristotle adds, to propose in temediates between contradictories is to initiate a process that will proceed ad infznitum, for each intermediate can in turn i tself be denied with reference to its own assertion and negation ( 1012a12- 15). Thus. just as between A and not-A there will be an intermediate B which is neither A nor not-A so from the same logic it follows that between B and oot-B there wi 11 be an intermediate C and so on in an infinite regress which is of course for Aristotle an anathema. ln the final analysis, Aristotk concludes, it is not possible even to assert an intermediate between contradictories. If someone on king asked whe

The beghmbg mmt be with definition (1012a17-28) While some of those who have failed to comprehend the true nature of the principles of reality have done su simply from a lack of comprehension, there are others who, insist on a reason for everything. The point must be established once more; against those who believe that there can be an intermediate between contradictories, and indeed al1 those who have acquired such paradoxical opinions, the start must be from definition, ah6h rpiq ij'awrvras roVro~kc bpra)roû ( 1012a21-22). To argue othenwise leads to an inhite regress eliminating al1 possibility of the demonstration of anything ( 1006a89). The logid detenninants of all definition, are those fundamentai axioms of knowing and being which have been subject to such extensive examination in Book T. Reflecting on what has emerged from the discussion, Aristotle concludes that the accounts of Heraclitus and Anaxagoras are, in fact., incompatibIe with one another since there is an inherent contradiction to be observed between Hemclitus' supposition that everything is 'so and not sol, which makes everything me, and that of Anaxagoras that there cm be an intemediate between coatradictories, which makes everythinp false ( 101îaî4-28).

140 Ross, following Alexandm and amûza &nie sees this as the correct interprctation of Aristotie's meaning. W.D. Ross, histotle's Metuphysics v. 1,. 2% note I0i 2a 13. TOWARDS A THEOLOGY: THE UNITY OF THINKING & BEING

Définition is the basis of knowing (lQl2a29-1012b22) In view of al1 that has been said. i t is apparent that the arguments purporting to refute the PNC and Pi34 as the most fundamental unhypothetical principles of thinking and king cannot withstand a critical appraisai of their merits. In drawing to a close Book T, Aristotle revisits some of the conclusions arrived at in ï4-7, beginning with the reafhnation that it is thmugh definition that being is made meaniogful to thought. It is impossible to agree either w ith Heraclitus that dl things are true or wi th Anaxagoras that al1 things are fdse. The response to al1 those who through their adoption of such one-sided positions would deny reality to the sensible is nof however. to start by asserting that mething is or is not, which as bas been noted might be seen as begging the question (1006a20). The beginning must be with definition, something that is meaningfd to dl concerned.

Ço that we must argue €romdefinition taking something to signify what is true or false. The ongins of our knowing are to be discovered in that unity of thinking and being with which vok av0poinvoç begins its self-realization through the intuition of the forms inherent in sensible substances. l-" If substance as the object of this science is to be known in and through itself and not in some extemal logic of connection. to begin with thinking must be at the sarne time to begin with king so that thoughts are not a succession but a unity, &E )Lil~bh@d& àAX Ev (lû27b24). In the intuition of essences as simple concepts, =pi S& 5à ai TU ri Eanv. there is no truth or falsity for thoughhi ( 1027b27-28). From the intuition of essence proceeds a definition, a formula which is expressive of the intrinsic meaning of a concept itself uohypothetical. In coming to know the essence of things vo* avûpoinvog cornes to know itself. however. caught in the extemality of space and tirne, it can never be that complete and actual unity of knowing and king that is its ci&, a thinking, thinking on thinking. fi vhcqv6qmztq vCIT((SLS ( 1û74b34).

It was from this understanding of the nature of human knowing that the examination of the Heraclitean rejection of the PNC began, as fmm the narne 'man'the definition expressed by the formula of the essence of 'man' was ideniifi~edas 'biped animal'. in the ensuing

14i Although not part of the discussion in r rhe argument hmthe De Anima 42kY-29 IS to be uncicrstood hem. proposition 'man is a biped animal' is the assurnption of a logic of tnith or falsity (1012b7- 8). Following the refutation of the Heraclitean position wi th the concomitant establishment of the logic of non-contradiction, the argument against the position of Anaxagoras was initiated, not from a specific individual concept such as 'man' but from the side of logic with a universal definition of 'truth' as the assertion or denial of the unity of being with knowing. Under the tems of their definition 'true' and Ydse' are reciprocdy exclusive. and so contradictory in accord with the PNC. Taken together in a logic of 'either' 'or' in accord wi th the PEM, îhey are ail-encompassing. 1t is thmfore intnnsic to the defini tion of truth and falsity that nothing can be both true and fdse and everything must be either tme or

But if that which is true to assert is nothing other than what is false to deny, it is impossible for everything ta be faIse. For it is necessary that one side of the contradiction is true. Again, if it is necessary either to assert or deny everything, it is impossible for both to be false; for it is one side of a contradiction that is faise. With a proper understanding of the nature of truth and falsity i t is evident that the views of both Heraclitus and Anaxagorus are necessarily self-destrtctive. Anyone who would go so far as to claim ihat 'everything is me' must accept by the same logc that the opposiog assertion that 'everything is faise' is dso tme. Anyone, on the other hand, who maintains that 'everything is false' by that very assertion makes himself false ( 10 12b 15 18).

The estabiishment of the basis for the stabiiity of being (1012822-31) With the emergence of substance as principle and cause, the movement of thought in Book r has kenable to transcend the &nopiaiwhich blocked the path to the identification of the object of a rrph@bao+ia. As principle, substance has ben shown to be the central conception of being and unity, ~pOçÉv (Il-2). As cause, it has been found to define 'w bat is and is one' and to delineate it from dl that it is not through an operational logic which extends to the wbole of reality (l3-7).However, although the framework for a metaphysics is now in place and its anchorbolts have been firdy grounded, Anstotie has kept alive throughout the discussion in ï the realization that the work is as yet incomplete. Always present as an undercurrent and periodically rippling across the surface of the argument has been the problern of 'rest' and 'motion', the relation of what is potential to what is actual, and in particuiar the ultimate dependence of the sensible on an unchanging nature, akivq705 $i>blç ( 10IOaM), which as full y actual is the unhypothetical fint prînciple of dl. It is with îhis in rnind tbat Anstotle turns for a last time to being to conclude the discussion.

Looked at from the perspective of king it is now evident that it cannot be inre either to assert with Parme~desthat ail things are at rest or to submit as an alternative to the argument of Heraclitus that all things are in motion. The fact that there is a sensible worid of change in which assertions that at one time are tnie are at another time not true is self- evident, Aristotle maintains

For if al1 things are at rest, the same thing will always be true and the same always fdse, and it is clear this changes. Change is no&only accidmtal. sensible substance itself is subject to change through generation and corruption so that he who makes a statement once was not and at another time will not be (101252526).'~f The actuality of sensible substance is always incomplete, thus Aristotie intimates, the unity of knowing and beiog that is achievable by voy MpOnivqis necesarily lirnited. Upon generation, each individual human MUS, as the form of a body, begins i ts actualization hou& the mediation of the senses on1y to have its substantial king and its accumulated knowledge pass away in time. Nevertheless, w hile i t is true that things change and hence are unable to maintain thernselves as full y actualized, it cannot be accepted, following the extended examination of this question in Book T, that the sensible is without a locus of stability and that everything is in flux.

But if everything is in motion, nothing will be true, indeed everything will be faise. But this has been shown to be impossible.

Since neither of these extreme positions, identifiable with those adopted by Parmenides and Heraciitus, can any longer be plausibly maintained, it must be concluded that reality is compriseci both of the changing and the unchanging, that which is in motion and that which is at rest To bring these two aspects of reality into a single view is the challenge that faces Hato and Aristotle in tm. In Aristotle's conception, Plato has failen short of his goal; unable to brîng matter fully under the dominion of fom, he has been forced to retreat to an

142 It seems appropriate to itssume, @vcn the diraion ihe discussion iakes, that Arisiorlc is deliberateiy shifting the focus from the object concerning which assertions are made to substance as the knowing subject In fact, Kirwan, p. 12 1 note 10 1ZbZ?, has criticized Aristode's position as 'unreasonable if i t holds that an assertion dters its cruth-vdue whcn iis assertor dies' abstraction beyond the sensible leaving behind what is other, non-king as E~epov.A full solution to the pmblem. for Aristotle, must begin with substance as what is and is one; that which out of its own nature reveals to thought the integral unity which underlies and sustains it in its self-identity and difference. What undergoes change must be something that already is, En W&yq sb Ôv pzawAkiv( 1012bîû) and change, Anstotle reiterates. is always hmsome thing to some thg, &K nyyàp & n fi pe~a&G(I012bîû-29)- Through this process of change there is always that which underlies and persists, substance as essence, to which is detennined ail that is accidentai. non-king as GUvapiç npk n.

In a world of motion and change the essential natures of sensible substances are the unmoved movers that underiie and stabilize the changing. Nevertheles. confined within the sensible as enmattered fonns, these unchanping natures are defective and must perforce be part of a ceaseless cycle of generation and destruction as individual prirnary substances corne into king and pass away. Sensible substance with its principle of essence as finite identity is an incomplete achiality, sustained through a logic of non-contradiction against the negativity which constrains it; a &pqac~ which is the mark of its derivativeoess and dependence upon the pnor unity of its apXii. It is in the berarchical ordering of dity. é@6~,to what is ultimately prior, forma1 cause as a principle of self-identity, that Aristotle sees ihat content is ultimately brought into full and perfect unity with forrn. Sensible substance in ail its rich diversity is encornpassed within the self-identity of np6q its principles held in potency in what is prior. the complete actuality of a first mover itself unmoved.

But again not everything is at rest or in motion at one time but nothing for ever. For there is çomething which always moves that which is moved, and the first mover is itseli unmoved- With these words Aristotle brings to a close the discussion in Book r. This science has broken free from the scepticism that would deny itsubstantiality and caught sight of the path to be followed towards its ultimate goal as BeoAayikil. The unmoved mover is that perfect unity of thinking and being to which the sensible is ordered and without which there can be no motion, no physics. Beyond the enmattered foms trapped forever in a wortd of change, God as first principle and complete actuality reaches out to the whole of reality and orders it to one end. CONCLUSIONS

The metaphysical agenda of Book r is not, as so many have thought. compieted in TI -3 with the resp01lseto the first four kopiaiand the concomitant establishment of the conditions detenniaing the possibility and scope of a science of being. The challenge of Parmenides and the -und for Aristotle's own fmt philosophy is vested ultimately in solving the problem that is presented by change and showing how non-king. as that which is in motion, can be said to be. It is the primary opposition of the unchanging Pannenidean One and the ever-chaoging Heraclitean flux that is the unspoken and overarching ampia of Book r and in the emergent recognition in r4-8of Aristotfe's own fundamental metaphysical principles of essence and of potency and act there is found the basis for a new understanding of the nature of reality.

In establishing the infrastructure for his metaphysics in Book T. Aristotle identifies certain key relationships w hich ensure that 'this science' will be fully comprehensive of the w hole of reality . The four causes of the Physics. as the limiting parameters of the sensible, are the premises upon which the argument is founded. Illtimate causality, in accord with the limits it imposes imparts to universal being a definitive nature and allows Aristotle to assert that there is a science of kingcpvr being. A conception of reaiity in which al1 king is ootologically equivalent is found, however, to be inadequate. As the categoncal distinctions reality exhibits are captureci for thought, Aristotle moves hman ontology to an ousiology in which being is ordered npkEv to a central conception of substance. as that which is ontologically pnor and alone existent From an ousiology, the focus of the search for the object of the 'fint science' is sharpened to reveal it as an aitiology in which substance as formal cause emerges as the pri nciple sustaining the diversi ty of the sensible in a logic of finite identity. Through the laws of the understanding, the PNC and PEM, the essential nature of sensible substance is given definition for thought To say anything at al1 that is meaningful about a thing is to signify, whether directly or indirectly. an essentiai nature. However, simply to identify essence as a locus of stability in the sensibIe is in~~cient.If a 'ktscience' is to be tmly universal the principles of the understanding, as its fundamental laws, rnust be fully extensive of dlreality.

In the latter half of Book T, Arktotle turns to the question of non-king and. against the background of a seemingly interminable flux, the Aristotelian doctrine of potentiality and actuality begins to make its presence felt The K& Ev ontology of king as substance and essence explored in r 14, with its concomitant acceptance of the primacy of definition, is retained; the non-specif~clogic of non-king as É~pov,however, is found to be inadequate to account for sensible change. In r 5-û Anstotle establishes the basis for the extension of the logic of non-contradiction to include a new fom of non-being, the deteminate ontology of non-being as SGvajuç 14165n, through which the potentiality of the sensible is comprehensively ordered to its principle as wmplete actuality. 1t is in a proper understanding of the nature of contrariety and its relation to the unity and self-identity of substance that there Lies the key to the development of a unitary conception of metaphysics. Although contraries are not themselves the first priaciples. it is through a relationship of logical contrariety that the indeterminacy of the sensi Me is first given limi t for thoughi. Each of the accidental categories of kingadmits contrariety, and throuph the determinate relation of non-king as SUvapiç xpk n, this contmriety is reduced to a unity which is referred rrpbç Ëv to a primary essential unity in substance. It is thus that the logic of oon- contradiction, in w hich non-king is ézpov, is extended to include the Iogic of 6Uvapq np6ç n ,in which non-king is essence in potency; and the sensible at its most extemal is brought under the dominion of form as its principle.

In a worid of motion and change the essential natures of sensible substances are the unmoved rnovers that underlie and stabilize the changing. As enmattered fomshowever. these unchanging natures are themselves defective, part of a ceaseless cycle of generation and destruction as individual primary substances corne into king and pass away. Sensible substance, with its principle of essence as finite identity and logic of non-contradiction. remains always an actuality which is incomplete, dependeut upon the prior unity of its ap~fias that which is fully actud. The nature of this dependency Aristotle establishes in r through the positing of a successive hienuchical ordering of substance. E@E&, to that which is prior. What is prior. é@&3ç, contains what is posterior, in potency. Hence, in the banscendent unity of the first substance. formai cause as principle of self-identity. the sensible is contained potentially in the actuality of its apfi. Aristotle, as he successively establishes in Book r the xp6ç év, Svaptq npk n, and relationships, focuses the whole of reality in substance, oiiaia, as 'what is' and what 'is one', and orders it successively and hïerarchically to the unmoved mover, as that complete actuality whicb is the unity of king and knowing. In so doing, he is able to draw free of the scepticism of those for whom truth raides only in the subjectivity of appearances and reveai the direction that thought must follow towards its ultimate goal, this science as koliyr~& TEXTS AND TRANSLATIONS

Aristotle. An'stotle's Metaphysics. a revised text witb introduction and commentary by W. David Ross. 2 vol. Oxford: Clarendon Press, 1924, corrected 1953. -- . Aristotle's Metaphysics: Books M and N. translated with introduction and notes by Julia Annas. Oxford: Clarendon Ress, 1976. --- . Aristotle on Comhg-TiBe & Pmsing-Awuy. a revised text with introduction and commentary by Harold H. Joachim. Oxford: Clarendon Ress, 1922. ---- . 7kMc Works of Aris~otIe.ed. Richard McKeon. New York: Random House, 1941. -- The Catego~es.On Interpretm hior Anaiytics. trans. Harold P. Cooke and Hugh Tredennick. (beb Classical Library). London: Heinemann, 1938.

. DeAnimu. ed. W. David Ross. (Oxford Classicai Texts), Oxford: Clarendon Press, 1956. ---- . Metaphysica ed. Werner W. Jaeger. (Oxford Classical Texts), Oxford: Clarendon Press, 1967. ---- . The Physics. tram. Riilip H. Wicksteed and Francis M. Cornforci. 2 vol. (Loeb Ciassical Library), London: Heinemann, vol. 1, 1929, vol. 11. 1935. ------. Prior ovrd Posterior Anatytics. a revised text with introduction and commentaq by W.David. Ross. 2 vol. Mord: Clarendon Press, 1949. Diels, Hermann and Walther Kranz Die Fragmente Der Vorsokrutiker. 5th ed. Berlin: Weidemann, 1934-37.

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